Bug#891810: hplip not installable without systemd

[Juliusz Chroboczek <jch@irif.fr>]

>> My systems are configured to avoid installing systemd.  This makes it
>> impossible to install hplip:

> The 'systemd' package doesn't switch your init system,

I understad that.  However, I try, to the extent possible, to avoid
installing software that I don't understand on the machines that
I maintain, and I do not understand systemd.

I find it surprising that I cannot install the hpps binary without
installing systemd.

> This is not a bug in hplip, nor in any other package down the dependency 
> chain; hereby closing then.

I most respectfully disagree -- I should be able to install the hpps
binary without installing systemd.

Please reopen this bug.