There are several points during x509 extension creation which rely on
configuration options which may have been incorrectly parsed due to
invalid settings. Preform a value check for null in those locations to
avoid various crashes/undefined behaviors
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/23183)
