Stop registering oslo.messaging option
Stop registering oslo.messaging option

oslo.messaging actually registers itself its option at run-time, we just
need to set the right default as we do in aodh.messaging.

Closes-Bug: #1483107
Change-Id: Ibf2477ce21216f49549ae1b37b3109e878cabd5d

sileht/aodh,openstack/aodh,pczerkas/aodh,sileht/aodh,pczerkas/aodh,openstack/aodh