curl(1) needs to keep its claptrap shut

`pastish < input > output` or `%!pastish` inside vim
displayed the progress meter.  this is per docs:

PROGRESS METER
  curl normally displays a progress meter during  operations,  indicating
  the  amount  of  transferred  data,  transfer speeds and estimated time
  left, etc.

  curl displays this data to the terminal by default, so  if  you  invoke
  curl  to do an operation and it is about to write data to the terminal,
  it disables the progress meter as otherwise it would mess up the output
  mixing progress meter and response data.

  If you want a progress meter for HTTP POST or PUT requests, you need to
  redirect the response output to a file, using shell  redirect  (>),  -o
  [file] or similar.

  It  is not the same case for FTP upload as that operation does not spit
  out any response data to the terminal.

  If you prefer a progress "bar" instead of the regular meter, -# is your
  friend.
prevent curl(1) from emitting html for 404 etc