Codechange: Use EnumBitSet for WindowDefaultFlags.

src/music_gui.cpp

@@ -670,7 +670,7 @@ static constexpr NWidgetPart _nested_music_track_selection_widgets[] = {
 static WindowDesc _music_track_selection_desc(
 	WDP_AUTO, nullptr, 0, 0,
 	WC_MUSIC_TRACK_SELECTION, WC_NONE,
-	0,
+	{},
 	_nested_music_track_selection_widgets
 );
 
@@ -929,7 +929,7 @@ static constexpr NWidgetPart _nested_music_window_widgets[] = {
 static WindowDesc _music_window_desc(
 	WDP_AUTO, "music", 0, 0,
 	WC_MUSIC_WINDOW, WC_NONE,
-	0,
+	{},
 	_nested_music_window_widgets
 );