GTG crashes at startup

[drtsdgdj]

Context: Startup

Traceback (most recent call last):
  File "/app/lib/python3.9/site-packages/GTG/gtk/application.py", line 110, in do_startup
    for backend_dic in BackendFactory().get_saved_backends_list():
  File "/app/lib/python3.9/site-packages/GTG/backends/__init__.py", line 143, in get_saved_backends_list
    module = self.get_backend(settings.get('module'))
  File "/app/lib/python3.9/site-packages/GTG/core/config.py", line 164, in get
    raise ValueError(
ValueError: No valid configuration value or default value was found for %s in %s

Software versions:

• Getting Things GNOME! v0.6
• CPython 3.9.9 (main, Nov 10 2011, 15:00:00) [GCC 11.3.0]
• GTK 3.24.34, GLib 2.70.5
• PyGLib 3.42.2, PyGObject 3.42.2

[nekohayo]

Duplicate of #845