don't show the dummy window for the rest of the dialogs too on mac

atom/browser/native_window.cc

@@ -65,6 +65,7 @@ NativeWindow::NativeWindow(
       aspect_ratio_(0.0),
       parent_(parent),
       is_modal_(false),
+      is_osr_dummy_(false),
       inspectable_web_contents_(inspectable_web_contents),
       weak_factory_(this) {
   options.Get(options::kFrame, &has_frame_);