contrib/ansible: Use kubectl to set the server url in conf

Sometimes https://127.0.0.1:6443 can be written in the conf, the regexp does
not account for that.

Signed-off-by: Julien DOCHE <julien.doche@gmail.com>

roles/k3s/master/tasks/main.yml

@@ -58,10 +58,9 @@
     owner: "{{ ansible_user }}"
 
 - name: Replace https://localhost:6443 by https://master-pi:6443
-  replace:
-    path: ~{{ ansible_user }}/.kube/config
-    regexp: 'https://localhost:6443'
-    replace: 'https://{{master_ip}}:6443'
+  command: k3s kubectl config set-cluster default
+    --server=https://{{ master_ip }}:6443
+    --kubeconfig ~{{ ansible_user }}/.kube/config
 
 - name: Create kubectl symlink
   file: