securetty in Debian

[pyllyukko]

• #731656 - Please disable securetty by default
• https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=674857#25
• pam_securetty: silently ignore missing securetty file #158

FWIW, the latest login upload to unstable (1:4.7-1) dropped support for
/etc/securetty and removed that file on upgrades, due to the numerous
complaints it caused:

,----
| shadow (1:4.7-1) unstable; urgency=medium
|
| [ Balint Reczey ]
| * Stop shipping and honoring /etc/securetty
| (Closes: #731656, #830255, #879903, #920764, #771675, #917893, #607073)
`----

This lead to complaints by pam_unix in the system logs on every login,
see #931899. I think it's time to disable pam_securetty by default, it
was useful twenty years ago but it no longer is.

[pyllyukko]

If distros don't use securetty it shouldn't still matter if the configuration exists. Also to play it safe we should have this conditionally and inspect PAM's configuration for pam_securetty which would introduce unnecessary complexity.