ThemeKit blocks menu bar icon tint update on macOS 11

[teologov]

Hi, I noticed a bug when NSStatusBarButton icon tint doesn't update dynamically when using ThemeKit. Setting button.isTemplate=true doesn't help. It seems it just keeps either a dark or light theme, even if ThemeManager.systemTheme is applied.

Note: it works as expected with button.isTemplate=true without ThemeKit.