python tests: Make test even more compatible with Python 2.6
python tests: Make test even more compatible with Python 2.6

Tojaj/librepo,bgamari/librepo,cgwalters/librepo,cgwalters/librepo,Conan-Kudo/librepo,cgwalters/librepo,rholy/librepo,rpm-software-management/librepo,bgamari/librepo,Conan-Kudo/librepo,cgwalters/librepo,Conan-Kudo/librepo,rholy/librepo,rholy/librepo,Tojaj/librepo,rpm-software-management/librepo,rpm-software-management/librepo,rholy/librepo,bgamari/librepo,Tojaj/librepo