Typo in backwards compat names for notification drivers

The switch to oslo.messaging uses setup.cfg to provide a mapping
for the Nova notification drivers, but mis-spelt them.   This will
break any existing Nova systems that use notifictaions for things
like billing, monitoring, etc

Change-Id: I217d6b68a64ee008a82426b890a32a97b849cb4d
Merge "Typo in backwards compat names for notification drivers"