The transitional behaviour was complete before oldoldstable and is no
longer relevant. Moving this snippet will eventually enable us to
remove the preinst for login completely (when the /etc/securetty
removal is complete). This will both reduce the total number of
maintscripts and also enable us to simplify deployment DPKG_ROOT (the
InstallBootstrap spec).
* https://wiki.debian.org/Teams/Dpkg/Spec/InstallBootstrap
Signed-off-by: Niels Thykier <niels@thykier.net>