Bug#1072182: delta: upstream location and 2020-06-22 release

[Matt Taggart <matt@lackof.org>]

Package: delta
Version: 2006.08.03-13

Maybe the upstream for delta is now

https://github.com/dsw/delta

There was a release on 2020-06-22 which is newer than what the package 
is using, although looking at the commits it's mostly just documentation 
changes.

popcon doesn't show many people using this, but if you care about it 
please adopt it!

--
Matt Taggart
matt@lackof.org