Additional check for synchronization helpers, if HA was enabled

Additional check for synchronization helpers, if HA was enabled for service on node attaching to cluster

This fix bug 895780
https://bugzilla.novell.com/show_bug.cgi?id=895780
This is not correct: you can't assume that `node[cookbook][:ha][:enabled]` is where the HA-enabled attribute lives. Needs some further thoughts on how to properly fix this :/