[ANNOUNCE] Queryable State is Broken on Master

[Aljoscha Krettek-2]

Our recent changes to make keyed state rescalable/key-group aware are
breaking queryable state because it is not yet made key-group aware. I
opened this Jira issue to track the fix for that:
https://issues.apache.org/jira/browse/FLINK-4556.

Sorry for the inconvenience.

Cheers,
Aljoscha