Fix build when Kross is not installed in the system
Review Request #128345 - Created July 2, 2016 and submitted
"include" paths were broken in https://phabricator.kde.org/D1862
Build problem on CI: https://build.kde.org/job/kross%20master%20stable-kf5-qt5/PLATFORM=Linux,compiler=gcc/125/console
Builds OK on my machine after uninstalling Kross from the system.