issue #1992 redirect status to log service if threading service has shut down

This patch catches a RejectedExecutionException that is thrown by the threading service after it has shut down. The StatusService tries to enqueue a status message during shutdown, but the threading service isn't there any more to pass it onto the event thread. I catch the exception and redirect the message to logging - I think that's appropriate at that point since there's no UI to display the status.