See https://github.com/baymac/gitlab-branch-source-plugin/pull/5#discussion_r291257804
Removed HashMaps as there are not necessary. As Joseph said,
On a big team they would use an individual Jenkins instance as well. Also usually most people have a CI user that they can just give access to their projects.
See https://github.com/baymac/gitlab-branch-source-plugin/pull/15