Add wait loop for RabbitMQ

rabbitmq/etc/init.d/rabbitmq

@@ -14,6 +14,10 @@ start() {
 	rabbitmq
 }
 
+start_post() {
+	timeout -t 3 docker exec rabbitmq sh -c 'until grep -q "Server startup complete" /var/log/rabbitmq/rabbit@rabbitmq.log 2>/dev/null ; do usleep 50000; done'
+}
+
 stop() {
 	/usr/bin/docker stop rabbitmq
 }