make sure url is null not ''

files/routes/admin.py

@@ -499,6 +499,8 @@ def badge_grant_post(v):
 			if '\\' in url: abort(400)
 			if url.startswith(f'{SITE_FULL}/'):
 				url = url.split(SITE_FULL, 1)[1]
+		else:
+			url = None
 
 		existing = user.has_badge(badge_id)
 		if existing: