[ADDED] SITE_URL usage in templates

Instead of {{ request.scheme }}://{{request.get_host}}`

allianceauth/context_processors.py

@@ -5,5 +5,6 @@ from .views import NightModeRedirectView
 def auth_settings(request):
     return {
         'SITE_NAME': settings.SITE_NAME,
+        'SITE_URL': settings.SITE_URL,
         'NIGHT_MODE': NightModeRedirectView.night_mode_state(request),
     }