CURLOPT_ERRORBUFFER(3) on macOS

The text cf99e796a39b, as OS X 10.11.6, OS X 10.11.5, OS X 10.11.4, OS X 10.11.3, OS X 10.11.2, OS X 10.11.1, OS X 10.11, OS X 10.10.5 shipped it.

set error buffer for error messages

CURLOPT_ERRORBUFFER(3) on macOS now