Merge pull request #1428 from timyinshi/kubeadm-join--control-plane

modify the error url of kubeadm

keps/sig-cluster-lifecycle/kubeadm/20190122-Certificates-copy-for-kubeadm-join--control-plane.md

@@ -74,7 +74,7 @@ support for high availability cluster is one of the most requested features for
 
 A lot of effort was already done in kubeadm for achieving this goal, among them the redesign
 of the kubeadm config file and its graduation to beta and the implementation of the
-[`kubeadm join --control-plane workflow (KEP0015)`](https://github.com/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/0015-kubeadm-join-control-plane.md),
+[`kubeadm join --control-plane workflow (KEP0015)`](https://github.com/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/kubeadm/0015-kubeadm-join-control-plane.md),
 but the solution currently in place stills requires the manual copy of cluster certificates from
 the bootstrap control-plane node to secondary control-plane nodes.
 
@@ -347,4 +347,4 @@ Several alternatives were considered:
     this was discarded due to the higher complexity
   - Creation of kubernetes job with the responsibility of reading certs from
     a bootstrap control-plane; this was discarded due to to the limited authorization
-    of the identity used by the kubeadm join workflow
+    of the identity used by the kubeadm join workflow