fix(POM): set fixed Maven install plugin
fix(POM): set fixed Maven install plugin

Due to MINSTALL-118 the Maven install plugin starting with version 3 demands a POM packaging for the Karaf assembly project. Due to it having a karaf-assembly packaging the version has to be set to the last 2.x version.

camunda/camunda-bpm-platform-osgi,camunda/camunda-bpm-platform-osgi