use async for WriteData

nksrv/LobbyServer/Msgs/Campaign/SaveField.cs

@@ -10,8 +10,6 @@ namespace nksrv.LobbyServer.Msgs.Campaign
             var req = await ReadData<ReqSaveCampaignField>();
             var user = GetUser();
 
-            Console.WriteLine("Map ID: " + req.MapId);
-
             var response = new ResGetFieldTalkList();
 
             Console.WriteLine($"save {req.MapId} with {req.Json}");
@@ -25,9 +23,7 @@ namespace nksrv.LobbyServer.Msgs.Campaign
                user.MapJson[req.MapId] = req.Json;
             }
 
-
-
-            WriteData(response);
+            await WriteDataAsync(response);
         }
     }
 }