Draggable demo: visual feedback - use draggable option stack selector…

…. Fixed #5513 - Draggable/Stackable Demo broken and docs need to be updated

demos/draggable/visual-feedback.html

@@ -27,7 +27,7 @@
 				return $('<div class="ui-widget-header">I\'m a custom helper</div>');
 			}
 		});
-		$("#set div").draggable({ stack: { group: '#set div', min: 1 } });
+		$("#set div").draggable({ stack: '#set div' });
 	});
 	</script>
 </head>