Update the versions used in the JDG 6.3, JDG 6.4, and Infinispan 7 POMs

I don't think we should push changes with internal versions - use -Djdg64.infinispan.version=6.2.0.ER2-redhat-1
You could change this in anticipation to 6.2.0.Final-redhat-1, but that wouldn't be much useful either so far.