Update curl-rust to handle SSL config for linuxes

Update curl-rust to handle SSL config for linuxes

Right now the cargo built on the snapshot bot isn't able to talk to the registry
due to failing to validate the SSL certificate. This is likely due to the
certificate path being hardcoded to something that's compatible with CentOS
(which isn't what I'm running locally).

I've modified curl-rust to use openssl-static-sys to probe the system for where
certificates are located and inform handles by default about the found
locations. This is the same strategy that git2-rs uses to inform openssl about
where the certificates are located.