CURLOPT_HTTPAUTH(3) on macOS

The text c7bb67273bc0, as macOS 10.12.5, macOS 10.12.4, macOS 10.12.3, macOS 10.12.2, macOS 10.12.1, macOS 10.12 shipped it.

set HTTP server authentication methods to try

CURLOPT_HTTPAUTH(3) on macOS now