[view.qt.thread] fix: crashing for custom actions that can request a system backup

CHANGELOG.md

@@ -33,6 +33,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - UI
   - crashing when resizing with floats instead of integers [#216](https://github.com/vinifmor/bauh/issues/216)
   - crashing when using floats for spinner components [#217](https://github.com/vinifmor/bauh/issues/217)
+  - crashing for custom actions that can request a system backup (e.g: Arch -> Quick system upgrade)
 
 ## [0.9.23] 2021-12-10
 ### Features

bauh/view/qt/thread.py

@@ -1025,7 +1025,7 @@ class CustomAction(AsyncAction):
         res = {'success': False, 'pkg': self.pkg, 'action': self.custom_action, 'error': None, 'error_type': MessageType.ERROR}
 
         if self.custom_action.backup:
-            proceed, _ = self.request_backup(app_config=CoreConfigManager.get_config(),
+            proceed, _ = self.request_backup(app_config=CoreConfigManager().get_config(),
                                              action_key=None,
                                              i18n=self.i18n,
                                              root_password=self.root_pwd,