oAuth Token Expiry Bug

Hi,

There seems to be a bug with this plugin where the oauth token that you provide when authenticating expires and causes the plugin to throw oAuth exception errors. This affects the plugin pages and other pages in the admin section like the Widgets area.

It would be best to either correctly refresh tokens (see: https://developers.google.com/identity/protocols/OAuth2WebServer#incrementalAuth) or at very least, fail gracefully once the token expires.

https://ww.wp.xz.cn/plugins/google-analyticator/