This ensures that request cancellation will be propagated properly to
the client used to create the stream. Without this fix, the apiserver
and the kubelet may leak resources (e.g., goroutine, inotify watches).
One such example is that if user run `kubectl logs -f <container that
don't produce new logs)` and then enter ctrl-c, both kubelet and
apiserver will hold on to the connection and resources indefinitely.
Kubernetes-commit: 31d1607a514b62ef46452e402f5438d827314b98
Yu-Ju Hong