D12905: KF5I18NMacros: Don't install an empty dir when no po files exist

[Luigi Toscano]

ltoscano added a reviewer: ilic.

REPOSITORY
  R249 KI18n

REVISION DETAIL
  https://phabricator.kde.org/D12905

To: heikobecker, ilic
Cc: kde-frameworks-devel, michaelh, ngraham, bruns