购物车未登录增加refer

@@ -18,7 +18,9 @@ const index = (req, res) => {
     let isLogin = req.user && req.user.uid,
         pageData = {
             isLogin,
-            signurl: helpers.urlFormat('/signin.html')
+            signurl: helpers.urlFormat('/signin.html', {
+                refer: req.originalUrl
+            })
         };
 
     // 唤起 APP 的路径