Traceback (most recent call last):
  File "/tmp/.mount_electryEwsaC/usr/lib/python3.9/site-packages/electrum/gui/qt/settings_dialog.py", line 437, in closeEvent
    self.unregister_callbacks()
  File "/tmp/.mount_electryEwsaC/usr/lib/python3.9/site-packages/electrum/gui/qt/util.py", line 1279, in unregister_callbacks
    self.qt_callback_signal.disconnect()
TypeError: disconnect() failed between 'qt_callback_signal' and all its connections