Fix segv for userids with a backslash.
Fix segv for userids with a backslash.

* src/engine-gpg.c (gpg_keylist_preprocess): Increment SRC for a
backslash.
--

This bug is not exploitable because this bug fills up .data with
backslashes and thus causes the segv.

Signed-off-by: Werner Koch <13bd1fc5137f503b0a8355ad400e7a87ebb45b25@gnupg.org>

gpg/gpgme,gpg/gpgme,gpg/gpgme,gpg/gpgme,gpg/gpgme,gpg/gpgme,gpg/gpgme