Cache the sreq inside the zmqchannel instead of caching the entire channel object.
Cache the sreq inside the zmqchannel instead of caching the entire channel object.

This is an improvement over #10332 in that you don't have to worry about someone creating a ZeroMQChannel then forking (thereby breaking the thread-pid rules). This way once it moves it will create a new sreq as needed.

This is possible now that #13155 is merged

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt