Update deprecated link in doc
Currently, the modified link is out of date. This patch aims to update
this link to the working one that user can access.
@@ -13,7 +13,7 @@ CoreDNS running the kubernetes plugin can be used as a replacement for kube-dns
cluster. See the [deployment](https://github.com/coredns/deployment) repository for details on [how
to deploy CoreDNS in Kubernetes](https://github.com/coredns/deployment/tree/master/kubernetes).
-[stubDomains and upstreamNameservers](https://blog.kubernetes.io/2017/04/configuring-private-dns-zones-upstream-nameservers-kubernetes.html)
+[stubDomains and upstreamNameservers](https://kubernetes.io/blog/2017/04/configuring-private-dns-zones-upstream-nameservers-kubernetes/)
are implemented via the *proxy* plugin and kubernetes *upstream*. See example below.
This plugin can only be used once per Server Block.
