CURLOPT_PREQUOTE(3) on macOS

The text 7f17e2a663d2, 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.

commands to run before FTP or SFTP transfer

CURLOPT_PREQUOTE(3) on macOS now