gpg: Fix output of --with-secret if a pattern is given.

* g10/keylist.c (list_one): Probe for a secret key in --with-secret
mode.

In contrast to list_all(), list_one() did not tests for a secret key
and took MARK_TRUSTED verbatim as an indication for "secret key
available".

GnuPG-bug: 4061
(cherry picked from commit 59d49e4a0ac2ed27803507cb7d2c6af166527bd5)

• Signed-off-by: Werner Koch <wk@gnupg.org>