close GUI if the network daemon is killed

gui/qt/main_window.py

@@ -181,6 +181,7 @@ class ElectrumWindow(QMainWindow):
             self.network.register_callback('banner', lambda: self.emit(QtCore.SIGNAL('banner_signal')))
             self.network.register_callback('status', lambda: self.emit(QtCore.SIGNAL('update_status')))
             self.network.register_callback('new_transaction', lambda: self.emit(QtCore.SIGNAL('transaction_signal')))
+            self.network.register_callback('stop', self.close)
 
             # set initial message
             self.console.showMessage(self.network.banner)

lib/network_proxy.py

@@ -86,6 +86,7 @@ class NetworkProxy(threading.Thread):
                 break
             self.process(response)
 
+        self.trigger_callback('stop')
         if self.network:
             self.network.stop()
         print_error("NetworkProxy: terminating")