Undo change to curl option from '--dump-header -' to '--include';

Commit b65b26 from 7Apr2013 includes (among other things) a change in four places to the an option passed to curl.  '--dump-header -' is replaced by '--include' (motivation unknown).  This works okay the first three places because no file is being written by curl, but the fourth change breaks file downloads by prepending HTTP headers to the file.

This trivial patch changes the option back to '--dump header -'.