Don't call OPENSSL_config(3)

The OPENSSL_config(3) man page claims that this function "ignores all
errors", but that's not true: at least OpenSSL 1.0.1e exit(3)s on
certain error conditions in the OPENSSL_config(3) function (e.g., if the
check whether the configuration file exists fails due to missing
permissions).  We therefore no longer call this function.