pki: Fix ecdsa key dup.

src/pki_crypto.c

@@ -348,6 +348,8 @@ ssh_key pki_key_dup(const ssh_key key, int demote)
             const EC_POINT *p;
             int ok;
 
+            new->ecdsa_nid = key->ecdsa_nid;
+
             new->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid);
             if (new->ecdsa == NULL) {
                 goto fail;