CURLINFO_FILETIME(3) on macOS

The text 03bdd2d776aa, 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.

get the remote time of the retrieved document

CURLINFO_FILETIME(3) on macOS now