Replaced ugettext and ugettext_lazy with gettext and gettext_lazy

ugettext and ugettext_lazy were deprecated in Django 3 and will be
removed in Django 4.

dav_auth/views.py

@@ -9,7 +9,7 @@ from django.http import HttpResponseRedirect
 from django.shortcuts import resolve_url
 from django.urls import reverse_lazy, reverse
 from django.utils.safestring import mark_safe
-from django.utils.translation import ugettext as _
+from django.utils.translation import gettext as _
 from django.views import generic
 
 from . import emails