add a check if the room is running

MafiaTelegramBot/Controllers/RoomController.cs

@@ -36,6 +36,7 @@ namespace MafiaTelegramBot.Controllers
                 if (!OpenedGames.ContainsKey(roomKey)) return ResultCode.RoomDoesNotExist;
                 var roomName = RoomEncrypter.GetName(roomKey);
                 if (!player.SetRoomName(roomName)) return ResultCode.UserAlreadyInGame;
+                if (OpenedGames[roomKey].IsRunning) return ResultCode.GameAlreadyRunning;
                 if (OpenedGames[roomKey].IsFilled()) return ResultCode.RoomIsFilled;
                 OpenedGames[roomKey].Players.Add(player.Id, player);
                 await OpenedGames[roomKey].PlayersCh.SendExcept(player.Id, $"{player.NickName} {strings.connected_to_game}");