x-add-key fails for attachments with quoted-printable transfer encoding

x-add-key fails for mails with an attached key, with Content-Transfer-Encoding: quoted-printable, and yields In the message you sent, no key could be found.

changed milestone to %3.5.1

added bug label

mentioned in commit 0e26a319

mentioned in merge request !334 (merged)

assigned to @georg

mentioned in commit 8babfe92

closed via merge request !334 (merged)