make tarball download url end in .tar.gz
follow up to #2037 (closed), Can we make the file name of tarball end with .tar.gz? Currently its like "archive.tar.gz?ref=v8.2.1"
for example https://gitlab.com/gitlab-org/gitlab-ce/repository/archive.tar.gz?ref=v8.2.1
is confusing for uscan (a tool used in debian to download new release tarballs)
gbp import-orig --pristine-tar --uscan gbp:info: Launching uscan... gbp:error: Couldn't find tarball at '../archive.tar.gz?ref=v8.2.1'
Where as github does it like this, https://github.com/github/linguist/archive/v4.7.2.tar.gz
and uscan can find it easily.