Since commit 426e70d4 (remote-curl: show server content on
http errors, 2013-04-05), we relay any text/plain error
messages from the remote server to the user. However, we
never tested it.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>