Fix missing break statement in ContainerScheduler#handle

case RECOVERY_COMPLETED:
  startPendingContainers(maxOppQueueLength <= 0);
  metrics.setQueuedContainers(queuedOpportunisticContainers.size(),
     queuedGuaranteedContainers.size());
//break;missed
default:
  LOG.error("Unknown event arrived at ContainerScheduler: "
    + event.toString());