Flasher stops responding when network dropdown is changed

[doudar]

If you have a network already selected and try to select a different network on in the UDP logging window, the program stops responding.

[doudar]

@MarkusSchneider - I'm a total python n00b but is it possible self.logging_thread needs to be stopped prior to self._logging_thread.start() in the def on_select_ip(self, event): ?

[doudar]

fixed by #13