Fix JBoss installation issue (metrics)

Fix JBoss installation issue caused by having the JBoss cartridges
depend on the jboss-openshift-metrics-module package. Installing the
metrics module first causes /etc/alternatives/jboss{as-7,eap-6} to be
created as a real directory, instead of as a symlink, which results in
the cartridge failing to start.
Merge pull request #5358 from ncdc/fix-jboss-metrics

Merged by openshift-bot