allow create-repo-list to be run without six
Some distros (gentoo) do not come with six in the base image (stage3),
it is installed later in the image build.  Use the native
urlopen/URLError if the six version is not available.
import os
import yaml
+try:
from six.moves.urllib.request import urlopen
+except ImportError:
+ from urllib.request import urlopen
+try:
from six.moves.urllib.error import URLError
+except ImportError:
+ from urllib.request import URLError
URL = ('https://opendev.org/openstack/project-config/'
'raw/gerrit/projects.yaml')
