Workaround XDG_CURRENT_DESKTOP=KDE is broken

[Boris Pek <tehnick@debian.org>]

Hi,

After recent update of KDE Plasma 5 in Debian Sid all KF5-based programs use
wrong Qt theme when they are launched in non-KDE environment or via SSH.
They look ugly and all icons from buttons, menus and list items are missing.
And previously working workaround [1] is completely broken.

Any idea which package is responsible for this?

[1] https://wiki.archlinux.org/index.php/qt#Configuration_of_Qt5_apps_under_environments_other_than_KDE

Best regards,
Boris