修改channel 获取方法

@@ -68,16 +68,16 @@ let index = (req, res, next) => {
  * @return {Function}
  */
 let switchChannel = (req, res, next) => {
-    let channel = req.cookies._Channel;
+    let channel = req.yoho.channel;
 
     // 如果查询字符串设置了 go 参数，跳转到 cookie 中设置的频道页
     if (req.query.go && channel) {
-        res.redirect('/' + channel);
-    } else {
-        // 设置浏览器缓存5分钟 300000ms
-        res.set('Expires', (new Date(_.now() + 300000)).toGMTString());
-        return next();
+        return res.redirect('/' + channel);
     }
+
+    // 设置浏览器缓存5分钟 300000ms
+    res.set('Expires', (new Date(_.now() + 300000)).toGMTString());
+    next();
 };
 
 /**