GitLab

The latter is only a wrapper around the former and it seems we want to remove
the latter from our shared common module.

Without this change, on fresh install, this module added its lines to a brand
new .gitignore, then etckeeper is installed and refuses to add its own standard
ignore lines because this file already exists and lacks the usual markers.

etckeeper package is installed.

Having it configurable would imply a lot more support.