Configuration: only produce a new configdata.pm if it has changed contents
The goal is to avoid having too much of the OpenSSL source rebuilt
because configdata.pm got a new time stamp. The conditions for
updating configdata.pm are now:
1. its time stamp is older than Configure's, or...
2. its contents has changed.
Fixes #16377
Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Todd Short <todd.short@me.com>
(Merged from https://github.com/openssl/openssl/pull/16378)