Move loopback_users line into main Dockerfile

Dockerfile

@@ -16,6 +16,8 @@ RUN grep -vE '^\s+-rabbit .*error_logger.*' /usr/lib/rabbitmq/lib/rabbitmq_serve
 	&& mv /tmp/rabbitmq-server /usr/lib/rabbitmq/lib/rabbitmq_server-*/sbin/rabbitmq-server
 ENV RABBITMQ_SERVER_START_ARGS -eval error_logger:tty(true).
 
+RUN echo '[{rabbit, [{loopback_users, []}]}].' > /etc/rabbitmq/rabbitmq.config
+
 VOLUME /var/lib/rabbitmq
 
 COPY docker-entrypoint.sh /

management/Dockerfile

@@ -1,6 +1,5 @@
 FROM rabbitmq:3.4.3
 
 RUN rabbitmq-plugins enable --offline rabbitmq_management
-RUN echo '[{rabbit, [{loopback_users, []}]}].' > /etc/rabbitmq/rabbitmq.config
 
 EXPOSE 15672