rtcompat: Set disable_built_in_roots with native_tls, to save memory with openssl
When using openssl on Linux, this saves us about 1.4 MB due to not loading the default CAs and CRLs (which Tor doesn't use.)
Addresses part of #1027.
When using openssl on Linux, this saves us about 1.4 MB due to not loading the default CAs and CRLs (which Tor doesn't use.)
Addresses part of #1027.