问如何阻止Google+登录按钮弹出消息“欢迎回来，您已通过Google+登录连接到此应用程序.....”

EN

<script type="text/javascript">
    (function () {
        var po = document.createElement('script');
        po.type = 'text/javascript';
        po.async = true;
        po.src = 'https://plus.google.com/js/client:plusone.js?onload=renderGPlus';
        var s = document.getElementsByTagName('script')[0];
        s.parentNode.insertBefore(po, s);
    })();
</script>

<script type="text/javascript">
    function renderGPlus() {
        gapi.signin.render('customGPlusBtn', {
            'callback': 'gPlusSignInCallback',
            'clientid': '<my_client_id>',
            'redirecturi': 'postmessage',
            'accesstype': 'offline',
            'cookiepolicy': 'single_host_origin',
            'requestvisibleactions': 'http://schemas.google.com/BuyActivity',
            'scope': 'https://www.googleapis.com/auth/plus.login https://www.googleapis.com/auth/userinfo.email'
        });
    }
</script>