If URLAvatarService is disabled, both the TravisCI and CircleCI
integrations will fail to create their service user. This is due to
attempting to access the URLAvatarService without checking if it is
enabled.

Here the fix is to check if it's enabled, then proceed with using the
service.

Ran the unit tests for both travisci and circleci integrations, as

well as manual testing with my jenkinsci code.