sm: Allow decryption even if expired other keys are configured.

sm: Allow decryption even if expired other keys are configured.

* sm/gpgsm.c (main): Add special handling for bad keys in decrypt
mode.
--

The problem can easily be tested by adding --encrypt-to EXPIRED_KEY to
a decryption command.  With that patch the errors are printed but
decryption continues and the process returns success unless other
errors occur.

GnuPG-bug-id: 4431
Signed-off-by: Werner Koch <wk@gnupg.org>
(cherry picked from commit 30972d21824264aef2088d30b4f2e5ce3aca889e)

Gbp-Pq: Topic from-2.2.15
Gbp-Pq: Name sm-Allow-decryption-even-if-expired-other-keys-are-config.patch