bpo-27513: email.utils.getaddresses() now handles Header objects (GH-13797) (GH-27242)

getaddresses() should be able to handle a Header object if passed
one.

Co-authored-by: Ɓukasz Langa <lukasz@langa.pl>
(cherry picked from commit 89f4c34797de2f0e5045da2b97c1c8cbbb42fbb2)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>
3 files changed