gpg: Don't use EdDSA algo ID for ECDSA curves.

* g10/keygen.c (ask_curve): Change algo ID to ECDSA if it changed from
an EdDSA curve.

(cherry picked from commit 4324560b2c0bb76a1769535c383424a042e505ae)

This change matters when it is called from ask_card_keyattr.

• Some-comments-by: NIIBE Yutaka <gniibe@fsij.org>