Bug#826587: apt: misleading message on trying to remove Important:yes packages

[Adam Borowski <kilobyte@angband.pl>]

Package: apt
Version: 1.2.12
Severity: minor

Hi!
When trying to remove an Important:yes package, the message claims it's
essential:

(gcc6-amd64-sbuild)root@umbar:/# apt-get purge init
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following package was automatically installed and is no longer required:
  sysvinit-core
Use 'apt autoremove' to remove it.
The following packages will be REMOVED:
  init*
WARNING: The following essential packages will be removed.
This should NOT be done unless you know exactly what you are doing!
  init
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
After this operation, 15.4 kB disk space will be freed.
You are about to do something potentially harmful.
To continue type in the phrase 'Yes, do as I say!'
 ?] ^C
(gcc6-amd64-sbuild)root@umbar:/# apt-cache show init
<...>
Important: yes
<...>

(gcc6-amd64-sbuild)root@umbar:/# dpkg --purge init
(Reading database ... 11961 files and directories currently installed.)
Removing init (1.34) ...