With modern apt-key, the fingerprints are displayed in the more fully
written-out format with spaces, and so `apt-key add` was being run
every time.
This fixes some unnecessary work being done on each puppet run on
Debian stretch.
I would have preferred to not need to do this by upgrading to
upstream, but see #7423 for notes on why that isn't going to work
(basically they broke support for puppet older than 4).
Tim Abbott
Tim Abbott
Luke Faraone
Zev Benjamin