Sometimes with some computers, the background notification were not d…

…isplayed. Trying to invoke the notification manager in another way. Some test show that it seem to work anytime now.

NAPS2.Core/WinForms/WinFormsOperationProgress.cs

@@ -89,7 +89,8 @@ public void ShowBackgroundProgress(IOperation op)
 
             if (!op.IsFinished)
             {
-                notificationManager.ParentForm.SafeInvoke(() => notificationManager.OperationProgress(this, op));
+                //notificationManager.ParentForm.SafeInvoke(() => notificationManager.OperationProgress(this, op));
+                notificationManager.ParentForm.Invoke(() => notificationManager.OperationProgress(this, op));
             }
         }