CURLOPT_USERPWD(3) on macOS

The text 26a96e724e60, 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.

user name and password to use in authentication

CURLOPT_USERPWD(3) on macOS now