Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/electrum/gui/qt/channel_details.py", line 264, in closeEvent
    self.unregister_callbacks()
  File "/usr/lib/python3/dist-packages/electrum/gui/qt/util.py", line 1664, in unregister_callbacks
    self.qt_callback_signal.disconnect()
TypeError: disconnect() failed between 'qt_callback_signal' and all its connections