Weighing: Fix scale L320 for Baden

Elwig/App.xaml.cs

@@ -183,6 +183,9 @@ namespace Elwig {
         }
 
         private async void Application_Exit(object sender, ExitEventArgs evt) {
+            foreach (var s in EventScales) {
+                s.Dispose();
+            }
             await Pdf.Cleanup();
         }