Allow to use a symbolic link instead of a local copy of the tar file for YunoHost backup that are already backed up.
This allow to reduce the size of the backup directory by not duplicate locally the tar YunoHost backups.
However, this can't be used with encryption, as an encrypted symbolic link does not contain anymore the link to the original file...
Fix https://github.com/YunoHost-Apps/archivist_ynh/issues/31
Allow to use a symbolic link instead of a local copy of the tar file for YunoHost backup that are already backed up. This allow to reduce the size of the backup directory by not duplicate locally the tar YunoHost backups.
However, this can't be used with encryption, as an encrypted symbolic link does not contain anymore the link to the original file...