keymgmt_meth: remove two TODO 3.0
keymgmt_meth: remove two TODO 3.0

The first TODO 3.0 is not really a TODO, just a comment.

The second one is something that is needed for compatibility
with existing applications. There is no major reason in
trying to change this behavior right now.

Fixes #14400

Reviewed-by: Shane Lontis <452ce16516ceed26291fe7de3f8b53540d83864e@oracle.com>
Reviewed-by: Paul Dale <ddec78389666b4f7c9b4d110380c848489a3e4aa@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14534)

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl