If an error occurs when parsing the content-type, check if the
content-type is quoted; if so, remove quotes. If this is not the case,
then return a text/plain content-type as a sane fallback option, so that
the message can be at least viewed in plaintext.
Fixes: https://todo.sr.ht/~rjarry/aerc/44
Signed-off-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>
