Fix: [Network] show query errors in the server listing instead of error popup (#9506)

When you are query several servers at once, it is rather unclear
for which server you got a popup. Instead, show any errors on the
server itself.

This is only true for the query-part. Joining a server still gives
an error popup to tell you about any issue.

src/network/network.cpp

@@ -632,7 +632,7 @@ public:
 	void OnFailure() override
 	{
 		NetworkGameList *item = NetworkGameListAddItem(connection_string);
-		item->online = false;
+		item->status = NGLS_OFFLINE;
 
 		UpdateNetworkGameWindow();
 	}