Mention that EVP_DigestInit() also clears all flags.
Fixes: 10031 Signed-off-by: Christian Heimes <christian@python.org> Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org> Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/10032)