Success update future after fetch future error [JIRA: CLIENTS-913] #632

• [ 2.0.6 ] Riak Java Client version
• [ 1.8 ] Java version
• [ 2.1.3 ] Riak version
• [ Mac OS X 10.11 ] Operating System / Distribution & Version
• [ UpdateValue.executeAsync ] What methods were being executed during the error
• What you expected to have happen: when I stop Riak, then I should have failed of all my new operation futures, but when I make UpdateValue, then I have success future.
• Sample data, if applicable:

    val update = new UpdateValue.Builder(location).withUpdate(...).build()
    client.executeAsync(update).addListener(
      new RiakFutureListener[UpdateValue.Response, Location] {
        override def handle(riakFuture: RiakFuture[UpdateValue.Response, Location]): Unit = {
          assert (riakFuture.isSuccess)
        }
      })

This assert is always true in my case, because exception writed at UpdateValue:216 (f.cause().getCause(), in my case NoNodesAvailableException#getCause()) is null and UpdateValueFuture#isSuccess checks exception field (UpdateValue:535)