fixed express child route jump correct

[sobird]

`var express = require('express'); var router = express.Router(); var CASAuthentication = require('cas-authentication');

var cas = new CASAuthentication({ cas_url : '', service_url : '' });

router.get('/', cas.bounce, function(req, res, next) { // to })`

例如上面代码按原来将会错误跳转，导致认证失败