initial-delay="null" when adding a new destination path

While following the tutorial from the wiki (https://wiki.opennms.org/wiki/Tutorial_Notifications), I figured that when you create a new destination path, the "default" value for the "initial delay" is "null", which didn't happen before. I mean, on Meridian 2016, the default is "0s" (which is a valid value).

This leads to a broken configuration which prevents the notifications to be sent, if you forget to fix it.