Update announcements.json

announcements.json

 [
+    {"id":18,"title":"大厅服务器目前升级中 暂停使用。 ","url":"https://my-card.in/","created_at":"2013-12-21T13:00:06+08:00","updated_at":"2013-12-21T13:00:06+08:00"},
     {"id":18,"title":"游戏王竞赛联盟~周赛","url":"http://www.duelcn.com/thread-59882-1-1.html","created_at":"2013-12-01T18:55:06+08:00","updated_at":"2030-10-22T10:34:06+08:00"},
     {"id":20,"title":"提示版本不匹配的请到官网下载1.2.8-1.2.9更新包，解压到mycard目录覆盖","url":"http://downloads.mycard.90g.org/updates/mycard-update-1.2.8-1.2.9.zip","created_at":"2013-11-27T10:34:06+08:00","updated_at":"2013-11-27T10:34:06+08:00"},
     {"id":19,"title":"更新807新卡","url":"http://goo.gl/1jn7tq","created_at":"2013-11-27T10:34:06+08:00","updated_at":"2013-11-27T10:34:06+08:00"},