Connection retries to shutdown node, see #3326

* In EC2 connection time out is around 1 minute. A few messages
  were sent after quarantining and these caused endless restarts,
  and connect attempts with 1 minute interval.
* This change makes sure that the endpoint is stopped after the first
  failed connection attempt.

We shall also discuss change of the default values for the retry window or how we can handle this problem when quarantining is not involved, because I guess the same thing can happen then.