fix submit

@@ -50,6 +50,13 @@ const addTicket = co(function * (uid, sku, count, yohoCoin) {
 const submitTicket = co(function * (uid, sku, count, mobile, yohoCoin) {
     let result = yield api.submit(uid, sku, count, mobile, yohoCoin);
 
+    if (_.isEmpty(result)) {
+        return {
+            code: 500,
+            message: '人太多啦,稍后再试!'
+        };
+    }
+
     if (result.code !== 200) {
         return {
             code: result.code,