Since deployments for non-mediawiki repos require git_repo to be set, if
git_repo isn't set when creating a lock file, that lock file is to
prevent the deployment of the mediawiki repo.
This caused problems when the git_repo was set in
/srv/mediawiki-staging/scap/scap.cfg. Since scap only looks for
configuration files in /etc/scap.cfg and ./scap/scap.cfg when
deploying from /srv/mediawiki-staging git_repo was set creating the
lockfile /var/lock/scap.operations_mediawiki-config.lock; however,
when running scap sync from /srv/ (or anywhere other than
/srv/mediawiki-staging) scap looked for the lockfile
/var/lock/scap.unknown-but-probably-mediawiki.lock. This allowed
parallel deploys of mediawiki to happen under certain circumstances
which causes unforeseeable issues.