[Bug]: QueryNode may panic during sending rpc to worker

[weiliu1031]

Is there an existing issue for this?

• I have searched the existing issues

Environment

- Milvus version: master and 2.4
- Deployment mode(standalone or cluster):
- MQ type(rocksmq, pulsar or kafka):    
- SDK version(e.g. pymilvus v2.0.0rc2):
- OS(Ubuntu or CentOS): 
- CPU/Memory: 
- GPU: 
- Others:

Current Behavior

if querynode lost connection to worker, and try to reconnect to worker again, due to logic error, querynode may panic.

Expected Behavior

No response

Steps To Reproduce

No response

Milvus Log

No response

Anything else?

No response

[weiliu1031]

/assign