a756b0c1a1
previously the BackGroup trait used the datastore's namespace_path() method to construct a base path. this would result in it returning an absolute path equivalent to full_group_path(). use the namspace's path() method instead to get a relative path, in-line with backup_dir's relative_path(). Signed-off-by: Stefan Sterz <s.sterz@proxmox.com>