App crashes on fetch tweets

[peter-budo]

Steps to reproduce:

1. Fresh install, and start app
2. On pop, G+ Create a profile, press cancel
3. In navigation drawer press Social
4. App crashes

12-22 14:32:07.925  25689-25689/com.conferenceengineer.android.iosched.event1208 W/iosched_BaseActivity﹕ No view with ID main_content to fade in.
12-22 14:32:07.937  25689-25944/com.conferenceengineer.android.iosched.event1208 E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #2
    Process: com.conferenceengineer.android.iosched.event1208, PID: 25689
    java.lang.RuntimeException: An error occured while executing doInBackground()
            at android.os.AsyncTask$3.done(AsyncTask.java:300)
            at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
            at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
            at java.util.concurrent.FutureTask.run(FutureTask.java:242)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
            at java.lang.Thread.run(Thread.java:818)
     Caused by: java.lang.StringIndexOutOfBoundsException: length=0; regionStart=0; regionLength=-1
            at java.lang.String.startEndAndLength(String.java:504)
            at java.lang.String.substring(String.java:1333)
            at com.google.samples.apps.iosched.social.twitter.TweetFetcher.getTweetsUrl(TweetFetcher.java:75)
            at com.google.samples.apps.iosched.social.twitter.TweetFetcher.fetchTweets(TweetFetcher.java:51)
            at com.google.samples.apps.iosched.ui.TwitterSocialFragment$StreamLoader.loadInBackground(TwitterSocialFragment.java:314)
            at com.google.samples.apps.iosched.ui.TwitterSocialFragment$StreamLoader.loadInBackground(TwitterSocialFragment.java:291)
            at android.content.AsyncTaskLoader.onLoadInBackground(AsyncTaskLoader.java:312)
            at android.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:69)
            at android.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:57)
            at android.os.AsyncTask$2.call(AsyncTask.java:288)
            at java.util.concurrent.FutureTask.run(FutureTask.java:237)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
            at java.lang.Thread.run(Thread.java:818)````