When the RPC and Notify service are the same, the credentials
must match - otherwise the tasks to create the user/password
will overwrite with each other.
If the two clusters are different, then the matching credentials
and vhost will not be a problem. However, if the deployer really
wishes to make sure they're different, then the vars can be
overridden.
Also, to ensure that the SSL value is consistently set in the
conf file, we apply the bool filter. We also use the 'notify'
SSL setting as the messaging system for Notifications is more
likely to remain rabbitmq in our default deployment with qrouterd
becoming the default for RPC messaging.
Change-Id: I0d5285eeebe94adda39b93e61e79be5673b7347d
51abb016b3