remove restriction when using open api

contest/views/admin.py

@@ -57,7 +57,7 @@ class ContestAPI(APIView):
         for ip_range in data["allowed_ip_ranges"]:
             try:
                 ip_network(ip_range, strict=False)
-            except ValueError as e:
+            except ValueError:
                 return self.error(f"{ip_range} is not a valid cidr network")
         if not contest.real_time_rank and data.get("real_time_rank"):
             cache_key = f"{CacheKey.contest_rank_cache}:{contest.id}"