devstack: use iniset_rpc_backend

Instead of calling get_transport_url directly.

Change-Id: Id6395be9da2c1074790115eeaf2fbeba0875cb38

Author: tobias-urdin

devstack/lib/magnum

@@ -135,9 +135,10 @@ function create_magnum_conf {
     rm -f $MAGNUM_CONF
     HOSTNAME=`hostname`
     iniset $MAGNUM_CONF DEFAULT debug "$ENABLE_DEBUG_LOG_LEVEL"
-    iniset $MAGNUM_CONF DEFAULT transport_url $(get_transport_url)
     iniset $MAGNUM_CONF DEFAULT host "$HOSTNAME"
 
+    iniset_rpc_backend magnum $MAGNUM_CONF
+
     iniset $MAGNUM_CONF database connection `database_connection_url magnum`
     iniset $MAGNUM_CONF api host "$MAGNUM_SERVICE_HOST"