Automatic merge from submit-queue
kubectl edit: Do not add warning header if ftype is json.
This PR blocks adding warning header if `kubectl edit` is used with `-o json` option.
Fixed header contains comment (what is not supported by json standard) what can break utilities which are using libraries that conforms with http://www.ietf.org/rfc/rfc7159.txtfixes#29524
/cc @pwittrock
```release-note
Removed comments in json config when using kubectl edit with -o json
```