Virtual media images can potentially contain sensitive data, such as
password hashes or private keys. This change adds TLS to this traffic.
A new HTTP server is now started with Nginx, serving the same /httpboot
directory as the old one. If vmedia_enable_tls is true, the /redfish
and /ilo directories are only accessible through it.
One of the redfish-vmedia CI jobs has been switched to using TLS.
Change-Id: I024b81efdbebe08ddb5a20cd0d5e7ae61a180f1b