rabbitmq-run.mk: Restart nodes in a cluster sequentially

... not in parallel.

(cherry picked from commit c0be3c0)
(cherry picked from commit 168c703)

Author: dumbbell

deps/rabbit_common/mk/rabbitmq-run.mk

@@ -435,7 +435,7 @@ restart-cluster:
 		  -rabbitmq_web_stomp_examples listener [{port,$$((61633 + $$n - 1))}] \
 		  -rabbitmq_prometheus tcp_config [{port,$$((15692 + $$n - 1))}] \
 		  -rabbitmq_stream tcp_listeners [$$((5552 + $$n - 1))] \
-		  " & \
+		  "; \
 	done; \
 	wait