Somehow when refactoring the CMakeLists and fixing the duplicated
definitions, the SIP options for Python 2 and Python 3 got swapped,
causing all sorts of subtle bugs (i18n() failing on Python3, encoding
errors from QString on Python 2). This patch fixes the behavior.

Thanks to Phil Thompson for finding out the cause.

This fix will also be forward-ported to master.

CCMAIL: kde-packager@kde.org