完善 refer

@@ -21,7 +21,7 @@ function doPassportCallback(openId, nickname, req, res) {
     if (refer) {
         refer = decodeURI(req.cookies.refer);
     } else {
-        refer = `${config.siteUrl}/?go=1`;
+        refer = `${config.siteUrl}/home`;
     }
 
     if (openId && nickname) {
@@ -47,7 +47,7 @@ const wechat = {
     beforeLogin: (req, res, next) => {
         let refer = req.query.refer;
 
-        res.cookie('refer', encodeURI(refer));
+        refer && res.cookie('refer', encodeURI(refer));
         next();
     },
     login: (req, res, next) => {