Morgan Adamiec authored Jun 17, 2021 and Allan McRae committed Jun 24, 2021

If the original download redirects to to a different url then alpm would
try to name the sig file after the url instead of <original_file>.sig.
Instead force this naming scheme regardless of url.

Fixes FS#71274

Signed-off-by: Allan McRae <allan@archlinux.org>