dget: add deb822 *.sources support

Osamu Aokirequested to merge
dgit-deb822 into main

Over restrictive sanity check has been relaxed

Signed-off-by: Osamu Aoki osamu@debian.org

This should fix https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=976673 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1030277

Merge request reports