Fixes Nova configuration for utilisation of Qpid for Telemetry

As reported in bug 1331903, without rpc_backend entry, Ceilometer
is unable to collect Qpid statistics. Now fixed for SUSE-based.

Note, this entry should already be put in place as per:
icehouse/install-guide/install/yum/content/nova-compute.html

If this is seen as too much duplication, I'll abandon. However,
without this, things don't work as expected.

Change-Id: Icaf4b3e99c20ddea3edf29dd8888206cb6177c83
Closes-Bug: #1331903