graphics/scrot new upstream

[N <ng0%n0.is@localhost>]

I noticed a thread on the openbsd-ports mailinglist,
where someone proposed to change the upstream URL since
http://linuxbrit.co.uk/scrot/ is "Not Found" (gone).

Instead of relying on one source I find it's good to
search for what others might find as a consensus or
a more stable source.

Debian started using
https://github.com/resurrecting-open-source-projects/scrot
as the new upstrean. Starting from that, Guix is using it
as well. FreeBSD ports switched to this source as well.

I propose we switch to this source, what do you think?