Don't ask L2 plugin question if Quantum is not isntalled.

Change-Id: If4295545538be807524b37f768259d52ff62ac36
Fixes: rhbz#967307
Open port for Quantum server

Change-Id: I3a8a9b932bd6f8213abe265fbed6961d15c57ce4
Fixes: rhbz#967291
Merge "Don't ask L2 plugin question if Quantum is not isntalled."