openssl: check for conf file

Closes #34728.
Why Bottles don't carry the ` openssl.cnf ` stuff? I'd guess because installing OpenSSL from source, specifying the ` HOMEBREW_PREFIX/etc ` directory that we do, everything is installed outside of the Cellar, and thus isn't included in the Bottle. At least, that's my theory. Mike is the bottle expert though, so if you and Mike don't know why this happens I'm probably screwed :wink:.