Fix #14475. Use IE11-friendly detect for proper XHR object.

We don't seem to have test cases for local file access.

src/ajax/xhr.js

@@ -6,13 +6,9 @@ define([
 
 // Create the request object
 // (This is still attached to ajaxSettings for backward compatibility)
-jQuery.ajaxSettings.xhr = window.ActiveXObject ?
-	/* Microsoft failed to properly
-	 * implement the XMLHttpRequest in IE7 (can't request local files),
-	 * so we use the ActiveXObject when it is available
-	 * Additionally XMLHttpRequest can be disabled in IE7/IE8 so
-	 * we need a fallback.
-	 */
+jQuery.ajaxSettings.xhr = window.ActiveXObject !== undefined ?
+	// Support: IE6+
+	// XHR cannot access local files, always use ActiveX for that case
 	function() {
 		return !this.isLocal && createStandardXHR() || createActiveXHR();
 	} :