We must call Email::Simple methods directly in our monkey patch
for Email::MIME to call the intended method. Using SUPER in our
subclass would instead hit a different, unintended method in
Email::MIME.
Reported-by: Junio C Hamano <gitster@pobox.com>
<xmqq4m0wb43w.fsf@gitster.mtv.corp.google.com>