updatefile() doesn’t work with _link files since meta=False by default,
and OBS gives 404 when this file is requested.

This workaround skips _link when it’s found, resulting in breaking the
link to the parent package. A proper fix would involve preserving _link,
but it’s not clear what is the best way to achieve that.

Signed-off-by: Andrej Shadura <andrew.shadura@collabora.co.uk>