Config migration: gajim crashes at startup: KeyError: 'proxies' in optparser.py

This bug has been reported at the Debian package: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1015717

Versions:

• OS: Debian GNU/Linux bookworm/sid unstable (sid)
• GTK Version: 3.24.34
• PyGObject Version: 3.42.1
• GLib Version : 2.72.0
• python-nbxmpp Version: 3.1.0
• Gajim Version: 1.4.6

Traceback

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/gajim/gtk/application.py", line 389, in
_handle_local_options
    self._startup()
  File "/usr/lib/python3/dist-packages/gajim/gtk/application.py", line 231, in
_startup
    self._init_core()
  File "/usr/lib/python3/dist-packages/gajim/common/application.py", line 68,
in _init_core
    app.settings.init()
  File "/usr/lib/python3/dist-packages/gajim/common/settings.py", line 211, in
init
    self._migrate_old_config()
  File "/usr/lib/python3/dist-packages/gajim/common/settings.py", line 324, in
_migrate_old_config
    optparser.OptionsParser(str(configpaths.get('CONFIG_FILE'))).read()
  File "/usr/lib/python3/dist-packages/gajim/common/optparser.py", line 89, in
read
    self.update_config(old_version, new_version)
  File "/usr/lib/python3/dist-packages/gajim/common/optparser.py", line 147, in
update_config
    self.update_config_to_1194()
  File "/usr/lib/python3/dist-packages/gajim/common/optparser.py", line 203, in
update_config_to_1194
    for name in self.old_values['proxies']:
KeyError: 'proxies'

Steps to reproduce the problem

1. Start Gajim from old config profile