In our kube-dns manifest for 1.6 we often had an empty section,
normalization converted this to `{}` which causes `kubectl apply` to
fail.
We can simply skip empty objects when outputing.
We don't call klog.InitFlags yet, because that will cause a flag
redefinition error until we get everyone to stop using glog. That
will happen when we update to k8s 1.13.