Update header_decode to handle bare and non-bare quoted-printable chars
Update header_decode to handle bare and non-bare quoted-printable chars

Signed-off-by: Chris Lamb <711c73f64afdce07b7e38039a96d2224209e9a6c@chris-lamb.co.uk>

xtaran/debian-devel-changes-bot,lamby/debian-devel-changes-bot,lamby/debian-devel-changes-bot,sebastinas/debian-devel-changes-bot,xtaran/debian-devel-changes-bot,lamby/debian-devel-changes-bot