First preparations for Django >= 4.x

- Slight reformatting in some parts; Non-functional changes
- ugettext(_lazy) no longer available in Django > 4, changing to
  gettext(_lazy)
- Since django-openid-auth doesn't work with Django > 4 yet, we need to
  pin this project to Django < 4 until that issue is solved

config.py

@@ -6,7 +6,7 @@ Configuration overrides for settings.py
 import os
 import sys
 from django.urls import reverse_lazy
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import gettext_lazy as _
 from django.contrib.messages import constants as message_constants
 from ivatar.settings import BASE_DIR