Try/catched authorizationClient.startOrContinueAuth(request) in
LoginActivity.onResume(), since we have xperienced some crashes where
request could be null. If it catches an exception, it will show an
error-popup instruction the user to check that they have the latest
facebook app, and then try again. When they press "OK" in the popup, the
LoginActivity calls finish(), and the user is returned to the app where
they left.