The OK button in the Remote Push dialog sometimes needed to be clicked
twice in order to work. That's because whenever the Database Name field
loses focus, we would send out a request for the updated branch list.
While processing this request the OK button is effectively disabled by
Qt. This commit aims for an easy fix by changing the request to happen
whenever the text in the Name field changes. This way the timing is a
lot less sensitive. We will need to see however if this introduces other
timing issues for users with slow Internet connections.