Currently, the contents of /var/lib/containers and /var/lib/image-serve diorectories are being backuped by ReaR without the possibility to choose whether we want or not those contents.

Those dirs contain the container images and as such are very big (taking around 54GB of a total of a 64GB backup). But the backup of the images is not that necessary, as they would be automatically downloaded from the registry whenever the rest of the node is restored.

Excluding that directories will largely improve backup and restore times.