Merge branch 'develop' of http://47.244.231.31:8099/zhl/globalso-v6 into bate

@@ -67,7 +67,7 @@ class MailController extends BaseController
     public function unreadNum(&$mailUserModel,$total){
         //已读数量
         $count = $mailUserModel->where(['user_id'=>$this->uid])->count();
-        $num = $total - $count;
+        $num = ($total - $count > 0) ? $total - $count : 0;
         return $num;
     }