core: Fix possible compliance mode detection error.

* src/verify.c (_gpgme_verify_status_handler): Insert missing break.

Before the insertion of the compliance status checking the break in
the default clause was used by the STATUS_PLAINTEXT code. That got
lost. I don't see any actual harm due to different values currently
in use for the compliance status.

• Fixes-commit: 05fa2a9c7764b28fdac35eb72631439df948ca0e
• Signed-off-by: Werner Koch <wk@gnupg.org>