App: Show scale errors always in debug mode

Elwig/App.xaml.cs

@@ -159,7 +159,7 @@ namespace Elwig {
                     list.Add(Scale.FromConfig(s));
                 } catch (Exception e) {
                     list.Add(new InvalidScale(s.Id));
-                    if (s.Required)
+                    if (Config.Debug || s.Required)
                         MessageBox.Show($"Unable to create scale {s.Id}:\n\n{e.Message}", "Scale Error",
                             MessageBoxButton.OK, MessageBoxImage.Error);
                 }