AkkaUtils askWithReply sleeps indefinitely when a timeout exception is thrown

When AkkaUtils.askWithReply gets a TimeoutException, the default parameters maxAttempts = 1 and retryInterval = Int.MaxValue lead to the thread sleeping for a good while.

I noticed this issue when testing for SPARK-6980 and using this function without invoking Spark jobs, so perhaps it acts differently in another context.

If this function is on its final attempt to ask and it fails, it should return immediately. Also, perhaps a better default retryInterval would be 0.