gpg: Change OID of Ed25519 and add Brainpool oids.
* common/openpgp-oid.c (openpgp_curve_to_oid): Change OID for Ed25519. Add brainpool OIDs. (openpgp_oid_to_curve): Ditto.
This change is required to the change in Libgcrypt. Note that we will
likely use a different OpenPGP algorithm ID for EdDSA and thus the
current Ed25519 implementation will not stay with us.
- Signed-off-by: Werner Koch <wk@gnupg.org>