Request header field Cache-Control is not allowed in Safari

The following code looks up a user's city from their IP address.

  jQuery(document).ready(function($) {

      var message = '';

      $.ajax({
        url: 'http://ift.tt/1In4Efd',
        type: "GET",
        success: function(result) {
          message = result.city + ' - ';
        }
      })
      .always(function(){
        $('.location span').html(message);
      });

    });

It works find except in Safari where it gives the error...

Refused to set unsafe header "Access-Control-Request-Headers" Failed to load resource: Request header field Cache-Control is not allowed by Access-Control-Allow-Headers.

How can I fix this?