Merge pull request #11 from joeribekker/patch-1

Added check if maintenance_until is not null

django_maintenance_window/management/commands/check_maintenance_mode.py

@@ -11,7 +11,7 @@ def handle(self, *args, **options):
         now = timezone.now()
 
         if config.maintenance:
-            if config.maintenance_until < now:
+            if config.maintenance_until and config.maintenance_until < now:
                 config.maintenance = False
                 config.maintenance_until = None
                 config.save()