CURLOPT_PROTOCOLS(3) on macOS

The text 839bc7c29fe7, 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 allowed protocols

CURLOPT_PROTOCOLS(3) on macOS now