Fix bddfcaef: don't tell twice that a client left because of a timeout etc (#8746)

SendError() notifies all clients of the disconnect. This calls
CloseConnection() at the end, which also notified the clients
of the disconnect. Really no need to do it twice.

The status NETWORK_RECV_STATUS_SERVER_ERROR is only set by
SendError(), so in case that is the status, don't let
ClientConnection() send another notification.

src/network/network_server.cpp

@@ -265,7 +265,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::CloseConnection(NetworkRecvSta
 	 */
 	if (this->sock == INVALID_SOCKET) return status;
 
-	if (status != NETWORK_RECV_STATUS_CONN_LOST && !this->HasClientQuit() && this->status >= STATUS_AUTHORIZED) {
+	if (status != NETWORK_RECV_STATUS_CONN_LOST && status != NETWORK_RECV_STATUS_SERVER_ERROR && !this->HasClientQuit() && this->status >= STATUS_AUTHORIZED) {
 		/* We did not receive a leave message from this client... */
 		char client_name[NETWORK_CLIENT_NAME_LENGTH];