External authentication logAuthenticationSuccess bug: user is undefined sometimes

```
[2014-02-05T15:46:46.462Z] ERROR: oae-server/18923 on release0: Unhandled error in the request chain, caught at the default error handler. (req.remoteAddress=127.0.0.1, req.remotePort=51925)
    GET /api/auth/google/callback?error=access_denied HTTP/1.1
    x-real-ip: 131.111.184.112
    x-forwarded-for: 131.111.184.112
    host: oae.oae-release0.oaeproject.org
    x-nginx-proxy: true
    cache-control: max-age=0
    accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
    user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/32.0.1700.107 Safari/537.36
    x-chrome-variations: CKy1yQEIlrbJAQiktskBCKm2yQEIwbbJAQihiMoBCLmIygEIjJPKAQiOk8oB
    referer: https://accounts.google.com/o/oauth2/auth?response_type=code&redirect_uri=https%3A%2F%2Foae.oae-release0.oaeproject.org%2Fapi%2Fauth%2Fgoogle%2Fcallback&scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.profile%20https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.email&client_id=832766182042-qh6jaoivvita7go298g7nevhcj6ghpci.apps.googleusercontent.com
    accept-encoding: gzip,deflate,sdch
    accept-language: en-US,en;q=0.8
    cookie: __utma=161612450.1036103470.1391594005.1391594005.1391594005.1; __utmc=161612450; __utmz=161612450.1391594005.1.1.utmcsr=t.co|utmccn=(referral)|utmcmd=referral|utmcct=/zklCp2ndQ3; connect.sess=s%3Aj%3A%7B%22passport%22%3A%7B%7D%7D.EhTEsaH%2FV59znqFRThD7cLN7CuegFzBa8s%2FIlqcT4Qs
    --
    TypeError: Object false has no method 'isTenantAdmin'
        at module.exports.logAuthenticationSuccess (/opt/oae/node_modules/oae-authentication/lib/util.js:96:29)
        at Object.module.exports.externalSuccessCallback (/opt/oae/node_modules/oae-authentication/lib/util.js:139:5)
        at /opt/oae/node_modules/oae-authentication/lib/strategies/google/rest.js:53:28
        at allFailed (/opt/oae/node_modules/passport/lib/middleware/authenticate.js:87:18)
        at attempt (/opt/oae/node_modules/passport/lib/middleware/authenticate.js:160:28)
        at Strategy.strategy.fail (/opt/oae/node_modules/passport/lib/middleware/authenticate.js:277:9)
        at Strategy.OAuth2Strategy.authenticate (/opt/oae/node_modules/passport-google-oauth/node_modules/passport-oauth/lib/passport-oauth/strategies/oauth2.js:101:17)
        at attempt (/opt/oae/node_modules/passport/lib/middleware/authenticate.js:337:16)
        at authenticate (/opt/oae/node_modules/passport/lib/middleware/authenticate.js:338:7)
        at /opt/oae/node_modules/oae-authentication/lib/strategies/google/rest.js:54:7```