KUser & KDE Print settings prompt root password

[Borden Rhodes <jrvp@bordenrhodes.com>]

As the subject says, on my Debian Stretch laptop, attempting to use
the KDE print settings or KUser prompts me to login with the root
account. This is a problem because I installed Debian with the root
account locked out. I thought Polkit was supposed to have taken care
of all of this. Perhaps I'm missing a package? I also reinstalled
kdesudo to no joy.

I'm sure other K settings apps are broken like this, too, but I
haven't found them yet.