SSLCertMonitor server-name parameter results in NPE

      <service name="SSL-Cert-HTTPS" interval="7200000" user-defined="false" status="on">
         <parameter key="retry" value="2"/>
         <parameter key="timeout" value="3000"/>
         <parameter key="port" value="443"/>
         <parameter key="days" value="30"/>
         <parameter key="server-name" value="${nodelabel}"/>
      </service>

2019-10-09 10:37:38,771 ERROR [Poller-Thread-3-of-30] o.o.n.p.p.PollableServiceConfig: Unexpected exception while polling PollableService[location=Default, interface=PollableInterface [PollableNode [1]:a.b.c.d], svcName=SSL-Cert-HTTPS]. Marking service as DOWN
java.lang.NullPointerException: null
        at java.util.regex.Matcher.getTextLength(Matcher.java:1283) ~[?:1.8.0_222]
        at java.util.regex.Matcher.reset(Matcher.java:309) ~[?:1.8.0_222]
        at java.util.regex.Matcher.<init>(Matcher.java:229) ~[?:1.8.0_222]
        at java.util.regex.Pattern.matcher(Pattern.java:1093) ~[?:1.8.0_222]
        at org.opennms.netmgt.poller.monitors.support.ParameterSubstitutingMonitor.parseString(ParameterSubstitutingMonitor.java:162) ~[org.opennms.features.poller.monitors.core-25.0.0.jar:?]
        at org.opennms.netmgt.poller.monitors.support.ParameterSubstitutingMonitor.lambda$getSubstitutedParameters$1(ParameterSubstitutingMonitor.java:113) ~[org.opennms.features.poller.monitors.core-25.0.0.jar:?]
        at java.util.HashMap.forEach(HashMap.java:1289) ~[?:1.8.0_222]
        at org.opennms.netmgt.poller.monitors.support.ParameterSubstitutingMonitor.getSubstitutedParameters(ParameterSubstitutingMonitor.java:110) ~[org.opennms.features.poller.monitors.core-25.0.0.jar:?]
        at org.opennms.netmgt.poller.monitors.support.ParameterSubstitutingMonitor.getRuntimeAttributes(ParameterSubstitutingMonitor.java:105) ~[org.opennms.features.poller.monitors.core-25.0.0.jar:?]
        at org.opennms.netmgt.poller.client.rpc.PollerRequestBuilderImpl.execute(PollerRequestBuilderImpl.java:177) ~[org.opennms.features.poller.client-rpc-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableServiceConfig.poll(PollableServiceConfig.java:135) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableService.poll(PollableService.java:190) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableElement.poll(PollableElement.java:309) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableContainer$5.run(PollableContainer.java:319) [opennms-services-25.0.0.jar:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_222]
        at org.opennms.netmgt.poller.pollables.PollableElement.withTreeLock(PollableElement.java:240) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableElement.withTreeLock(PollableElement.java:227) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableContainer.poll(PollableContainer.java:326) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableInterface.poll(PollableInterface.java:228) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableContainer$5.run(PollableContainer.java:319) [opennms-services-25.0.0.jar:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_222]
        at org.opennms.netmgt.poller.pollables.PollableElement.withTreeLock(PollableElement.java:240) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableElement.withTreeLock(PollableElement.java:227) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableContainer.poll(PollableContainer.java:326) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableNode$3.run(PollableNode.java:288) [opennms-services-25.0.0.jar:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_222]
        at org.opennms.netmgt.poller.pollables.PollableElement.withTreeLock(PollableElement.java:240) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableElement.withTreeLock(PollableElement.java:227) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableNode.doPoll(PollableNode.java:291) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableElement.doPoll(PollableElement.java:184) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableService.doPoll(PollableService.java:214) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableService$PollRunner.run(PollableService.java:60) [opennms-services-25.0.0.jar:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_222]
        at org.opennms.netmgt.poller.pollables.PollableElement.withTreeLock(PollableElement.java:276) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableElement.withTreeLock(PollableElement.java:259) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableService.doRun(PollableService.java:404) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.poller.pollables.PollableService.run(PollableService.java:379) [opennms-services-25.0.0.jar:?]
        at org.opennms.netmgt.scheduler.Schedule.run(Schedule.java:142) [org.opennms.core.daemon-25.0.0.jar:?]
        at org.opennms.netmgt.scheduler.Schedule$ScheduleEntry.run(Schedule.java:86) [org.opennms.core.daemon-25.0.0.jar:?]
        at org.opennms.netmgt.scheduler.LegacyScheduler$1.run(LegacyScheduler.java:179) [org.opennms.core.daemon-25.0.0.jar:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_222]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_222]
        at org.opennms.core.concurrent.LogPreservingThreadFactory$3.run(LogPreservingThreadFactory.java:124) [opennms-util-25.0.0.jar:?]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_222]