ChattyWindow: Don't set nonsense title

Setting to "Window" makes it look weird. See the little "Window" written
below chatty:

![with-app-id](/uploads/fae0a46633606f9c352956dfed9b7890/with-app-id.png)

In the long run it would be totally cool if it had the name of a
currently ongoing chat there.
3 jobs for drop-widow-title in 4 minutes and 26 seconds (queued for 3 seconds)