Changed OPENSSL_gmtime so macOS uses threadsafe gmtime_r instead of gmtime.

Updated uses of gmtime to now call OPENSSL_gmtime instead.

Used similar preprocessor logic to make sure localtime_r is called instead
of localtime when applicable.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3609)