v3.0.2 bug in open_node, fix - revert to 3.0.1 code

after 3.0.1 there is an error 'TypeError: callback is undefined jquery.jstree.js:1070'
If revert this part of code by v3.0.1 code, then it works.
I don't think this is good method, but it works now.

My script is:
```
$(function () {
	var tree = $("#tree").jstree({ 
	"core" : {
		"data" : {
		"url" : function(node) {
		return node.id === "#" ?
		"/services/lk_tree/?first=1&id2=" : "/services/lk_tree/";
		},
		"data" : function (node) {
		return {"id": node.id } ;
		}
		}
		
		}
	});
	
	$("#tree").on("select_node.jstree", function(e,data){
	if($("#tree").jstree(true).is_parent(data.selected) == false ){
		window.location.href = data.node.a_attr.href;
} else {
$("#tree").jstree(true).load_node(data.selected);
$("#tree").jstree(true).open_node(data.selected);

};
	
	});
	
	$("#tree").on("load_node.jstree", function(e,data){
	if($("#tree").jstree(true).is_leaf(data.node.id) === true ){
		window.location.href = data.node.a_attr.href;
}
		});
});
```