This header is sent by jQuery everytime you perform an AJAX request. You could try disabling it by globally subscribing to the ajaxSend
handler and overriding its value:
$(document).ajaxSend(function(event, jqXHR, ajaxOptions) {
jqXHR.setRequestHeader('X-Requested-With', {
toString: function() { return ''; }
});
});
Notice that this will only set the value of the header to an empty string. It won't remove it from the request. A bug has been filed
in jQuery asking to have the possibility to completely remove this request header and apparently it was rejected as not a bug.