reduce time for valid qr code

backend/website/routes.py

@@ -220,7 +220,7 @@ def generate_ticket():
     json_seed = json.loads(data.decode('utf-8'))
     epoch_timestamp = parser.isoparse(json_seed['timestamp']).timestamp()
 
-    if datetime.now(tzutc()).timestamp() - epoch_timestamp > 60.0:
+    if datetime.now(tzutc()).timestamp() - epoch_timestamp > 30.0:
         return 'error: oldseed', 400
 
     # sign RSA ticket with AES encryption