py: Use standard python exception while accessing bad attrs. (RhBug: 920673)
py: Use standard python exception while accessing bad attrs. (RhBug: 920673)

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