Fix file extension and remove not necessary sudo. (#7143)

* Fix file extension and remove not necessary sudo.

* Rename kube-proxy.сm to kube-proxy-сm.yaml for clarity.

docs/setup/independent/high-availability.md

@@ -490,9 +490,9 @@ Next provision and set up the worker nodes. To do this, you will need to provisi
 1. Reconfigure kube-proxy to access kube-apiserver via the load balancer:
 
     ```shell
-    kubectl get configmap -n kube-system kube-proxy -o yaml > kube-proxy.yaml
-    sudo sed -i 's#server:.*#server: https://<masterLoadBalancerFQDN>:6443#g' kube-proxy.cm
-    kubectl apply -f kube-proxy.cm --force
+    kubectl get configmap -n kube-system kube-proxy -o yaml > kube-proxy-сm.yaml
+    sed -i 's#server:.*#server: https://<masterLoadBalancerFQDN>:6443#g' kube-proxy-cm.yaml
+    kubectl apply -f kube-proxy-cm.yaml --force
     # restart all kube-proxy pods to ensure that they load the new configmap
     kubectl delete pod -n kube-system -l k8s-app=kube-proxy
     ```