RC buggy packages kept in testing due to d-i

[Niels Thykier <niels@thykier.net>]

Hi,

I noticed that apex and nis are currently testing despite the
auto-remover wanting to remove them (#865585 and #862778).  At the
moment, they are (only) retained due to a constraint that ensures that
d-i's packages are all present and installable.

Please have a look at these packages and let us know if this constraint
is still relevant.  Particularly, apex looks rather concerning with the
bug (#865585) being filed in Jun 2017 with no maintainer follow up at all.

Thanks,
~Niels