g10: fix cmp_public_key and cmp_secret_keys.
* g10/free-packet.c (cmp_public_keys, cmp_secret_keys): Compare opaque data at the first entry of the array when it's unknown algo. * configure.ac (NEED_LIBGCRYPT_VERSION): Require 1.5.0.
- GnuPG-bug-id: T1962