D27893: Use fallback also on Windows not only mac

[Hannah von Reth]

vonreth added reviewers: broulik, bcooksley, jjazeix, cullmann.

REPOSITORY
  R289 KNotifications

REVISION DETAIL
  https://phabricator.kde.org/D27893

To: vonreth, broulik, bcooksley, jjazeix, cullmann
Cc: kde-frameworks-devel, LeGast00n, cblack, GB_2, michaelh, ngraham, bruns