D27573: Fix issue finding the Boost include directories

[Daniel Albers]

dalbers added a reviewer: KActivities.

REPOSITORY
  R6 KActivities

REVISION DETAIL
  https://phabricator.kde.org/D27573

To: dalbers, #kactivities
Cc: kde-frameworks-devel, LeGast00n, cblack, GB_2, michaelh, ngraham, bruns