Fixed debugger call in E-mail.

* The settings view is no longer a direct child of the protocol settings
  view.

src/preferences/mail/ConfigViews.cpp

@@ -164,7 +164,8 @@ ProtocolSettingsView::DetachedFromWindow()
 	fSettings.MakeEmpty();
 	fSettings.Append(settings);
 
-	RemoveChild(fSettingsView);
+	// We need to remove the settings view before unloading its add-on
+	fSettingsView->RemoveSelf();
 	delete fSettingsView;
 	fSettingsView = NULL;
 	unload_add_on(fImage);