src: exclude node_root_certs when use-def-ca-store

When configuring node with --openssl-use-def-ca-store the root certs
from OpenSSL should be used and not the ones in src/node_root_certs.h.
I noticed that src/node_root_certs.h is still included even when
using --openssl-use-def-ca-store.

This commit adds check and does not include node_root_certs.h if
--openssl-use-def-ca-store is specified.

PR-URL: https://github.com/nodejs/node/pull/11939


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>