tests: Fix python3 syntax error in python test
tests: Fix python3 syntax error in python test

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