Fix kolflib_export

Summary: KOLFLIB_EXPORT Macro causes many linking errors when compiling with craft on windows using mingw and MSVC

Reviewers: #kde_games, cullmann

Reviewed By: cullmann

Subscribers: cullmann, aacid, vonreth, yurchor, kde-games-devel

Tags: #kde_games, #craft

Differential Revision: https://phabricator.kde.org/D24570