change `|` to `is` (#6991)

Since ansible 2.9 search cannot be used as filter after a pipe but after `is`

Signed-off-by: Sylvain Desbureaux <sylvain.desbureaux@orange.com>

roles/kubernetes/node/tasks/main.yml

@@ -139,7 +139,7 @@
 
 - name: Test if openstack_cacert is a base64 string
   set_fact:
-    openstack_cacert_is_base64: "{% if openstack_cacert | search ('^([A-Za-z0-9+/]{4})*([A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{2}==)?$') %}true{% else %}false{% endif %}"
+    openstack_cacert_is_base64: "{% if openstack_cacert is search ('^([A-Za-z0-9+/]{4})*([A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{2}==)?$') %}true{% else %}false{% endif %}"
   when:
     - cloud_provider is defined
     - cloud_provider == 'openstack'