OPENSSL_init_crypto(): check config return code correctly

It was assumed that the config functionality returned a boolean.
However, it may return a negative number on error, so we need to take
that into account.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8679)