Bug#1074098: Add Depends: login if applicable

Source: s390-tools

The login package has recently stopped being Essential: yes, and
thus could be absent on some installations.  However, most installs
will still have it, due to it being Priority: required.

If your package directly requires login in (almost) all
configurations, please add Depends: login. Or a lesser relationship
(Recommends, Suggests) if applicable.

Thanks,
Chris