Fix duplicate codes appearing in list

Fix the bug with appending the codes introduced in 1230689

Author: dreamsyntax

Source/HedgeModManager.UI/ViewModels/MainWindowViewModel.cs

@@ -351,7 +351,7 @@ public async Task LoadGameAsync()
             {
                 try
                 {
-                    await UpdateCodesAsync(Config.CheckCodeUpdates, true);
+                    await UpdateCodesAsync(Config.CheckCodeUpdates, false);
 
                     if (Config.CheckModLoaderUpdates)
                         await CheckForModLoaderUpdatesAsync();