Default callbackContext to the $.extended ajax options for 1.3.2 comp…

…atibility, per #5654.

src/ajax.js

@@ -199,7 +199,7 @@ jQuery.extend({
 		var s = jQuery.extend(true, {}, jQuery.ajaxSettings, origSettings);
 
 		var jsonp, status, data,
-			callbackContext = s.context || window,
+			callbackContext = s.context || s,
 			type = s.type.toUpperCase();
 
 		// convert data if not already a string