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

This reverts commit be98f269.

The above commit prevented the functionality of --use-bundled-ca if
Node has been built using --openssl-use-def-ca-store, since there will
be no bundled ca included and no way to use them.

I only noticed this when trying to add // Flags: --use-bundled-ca to
test-tls-ccnic-whitelist.js to force it to use the bundled ca and allow
the test to pass.

PR-URL: https://github.com/nodejs/node/pull/12391


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