JMX config GUI can't connect to JMX service with JNDI name not "jmxrmi"

The JMX URI pattern that we generate in the UI doesn't seem to handle custom JNDI names. This causes problems trying to connect to an Apache Karaf 4 process since Karaf uses "karaf-${name}" as the JNDI name for the MBean broker instead of the default value of "jmxrmi".

It's probably pretty unusual for a Java process to use anything besides "jmxrmi" so I'll keep this as a minor issue.