fix: Обработка отключения G2O сервера

src/pyg2o/server.py

@@ -130,6 +130,9 @@ class Server:
                     cls._logger.exception(f'Ошибка декодирования JSON: {e}')
         except WebSocketDisconnect:
             cls._logger.info('WebSocket клиент отключился')
+            if connection == cls._server_connection:
+                cls._server_connection = None
+            else:
                 playerid = next((key for key, values in cls._registered_clients.items() if connection in values), None)
                 if playerid is not None: cls._registered_clients[playerid].remove(connection)
         except WebSocketException as e: