Move rpc backend start/configure to earlier

Because things like nova may need to create vhosts in the rpc backend,
we need to have started and created credentials before we configure
the service.

Change-Id: I01c9c5288e197fc50a8a4a032e3a32cd166eb180
diff --git a/stack.sh b/stack.sh
index 94315e1..2f43db7 100755
--- a/stack.sh
+++ b/stack.sh
@@ -761,6 +761,7 @@
 run_phase stack pre-install
 
 install_rpc_backend
+restart_rpc_backend
 
 # NOTE(sdague): dlm install is conditional on one being enabled by configuration
 install_dlm
@@ -952,11 +953,6 @@
 fi
 
 
-# Finalize queue installation
-# ----------------------------
-restart_rpc_backend
-
-
 # Export Certificate Authority Bundle
 # -----------------------------------