Fix service start sequence

1. zmq-receiver should be started in advance
2. when using zeromq driver, nova-compute relies
on nova-conductor's rpc to be initialized

This fix is totally safe and won't influence
on other services.

Change-Id: I9d7b682df4d411af24a1ff6bcad79697e32fa723
Partially-Implements: blueprint zeromq
diff --git a/stack.sh b/stack.sh
index b064c22..3fa3212 100755
--- a/stack.sh
+++ b/stack.sh
@@ -1030,6 +1030,14 @@
 fi
 
 
+# ZeroMQ
+# ------
+if is_service_enabled zeromq; then
+    echo_summary "Starting zeromq receiver"
+    run_process zeromq "$OSLO_BIN_DIR/oslo-messaging-zmq-receiver"
+fi
+
+
 # Horizon
 # -------
 
@@ -1208,11 +1216,6 @@
     iniset $NOVA_CONF keymgr fixed_key $(generate_hex_string 32)
 fi
 
-if is_service_enabled zeromq; then
-    echo_summary "Starting zermomq receiver"
-    run_process zeromq "$OSLO_BIN_DIR/oslo-messaging-zmq-receiver"
-fi
-
 # Launch the nova-api and wait for it to answer before continuing
 if is_service_enabled n-api; then
     echo_summary "Starting Nova API"