修复重置消费进度时，没有Check订阅组是否存在的bug

Author: vintagewang

rocketmq-broker/src/main/java/com/alibaba/rocketmq/broker/client/net/Broker2Client.java

@@ -157,6 +157,12 @@ public RemotingCommand resetOffset(String topic, String group, long timeStamp, b
 
             long consumerOffset =
                     this.brokerController.getConsumerOffsetManager().queryOffset(group, topic, i);
+            if (-1 == consumerOffset) {
+                response.setCode(ResponseCode.SYSTEM_ERROR);
+                response.setRemark(String.format("THe consumer group <%s> not exist", group));
+                return response;
+            }
+
             long timeStampOffset =
                     this.brokerController.getMessageStore().getOffsetInQueueByTime(topic, i, timeStamp);
             if (isForce || timeStampOffset < consumerOffset) {