[ISSUE apache#8963] Fix code36 request sent to ns

Author: yx9o

client/src/main/java/org/apache/rocketmq/client/impl/consumer/DefaultMQPushConsumerImpl.java

@@ -767,6 +767,9 @@ private void sendMessageBack(MessageExt msg, int delayLevel, final String broker
             } else {
                 String brokerAddr = (null != brokerName) ? this.mQClientFactory.findBrokerAddressInPublish(brokerName)
                     : RemotingHelper.parseSocketAddressAddr(msg.getStoreHost());
+                if (UtilAll.isBlank(brokerAddr)) {
+                    throw new MQClientException("Broker[" + brokerName + "] master node does not exist", null);
+                }
                 this.mQClientFactory.getMQClientAPIImpl().consumerSendMessageBack(brokerAddr, brokerName, msg,
                     this.defaultMQPushConsumer.getConsumerGroup(), delayLevel, 5000, getMaxReconsumeTimes());
             }