Fix: don't do a network disconnect between two queries

This meant that on opening the Multiplayer window, if you had more
than one server configured, it would one by one cancel all pending
queries and send a new. Result: only the last server was updated.

src/network/network.cpp

@@ -628,11 +628,6 @@ private:
 public:
 	TCPQueryConnecter(const std::string &connection_string, bool request_company_info) : TCPConnecter(connection_string, NETWORK_DEFAULT_PORT), request_company_info(request_company_info), connection_string(connection_string) {}
 
-	void OnFailure() override
-	{
-		NetworkDisconnect();
-	}
-
 	void OnConnect(SOCKET s) override
 	{
 		_networking = true;
@@ -650,7 +645,6 @@ void NetworkTCPQueryServer(const std::string &connection_string, bool request_co
 {
 	if (!_network_available) return;
 
-	NetworkDisconnect();
 	NetworkInitialize();
 
 	new TCPQueryConnecter(connection_string, request_company_info);