* scd/app-nks.c (do_sign): Handle plain SHA-2 digests and verify
encoding of ASN.1 encoded hashes.
--
This makes it possible to create CSRs for NetKey card keys which are
signed with SHA256 by default.
GnuPG-bug-id: 5184
(cherry picked from commit 8fe976d5b9a0f2902868737dd502c749565222a6)