Cannot receive msg when the sub topic is re-subscribed by emqx

[xiangfangyang-tech]

1. emqx设定规则，sub主题时， a被重写成b
2. jmeter使用mqtt-xmeter-2.0.2-jar-with-dependencies.jar，进行连接及sub主题a，设置成必须收到1个消息
3. 用mqttx对emqx发送主题b
4. 发现jmeter中sub的控件一直收不到消息 ps.使用fuse插件则没有这个问题 mqtt-xmeter-fuse-2.0.2-jar-with-dependencies.jar