Replace skip with errors=ignore

Upstream deprecated "skip:" in preference of errors="ignore" [1].
Update playbooks to silence deprecation warning

[1] e17a2b502d

Change-Id: I72284f6ca8aaaa1ba5f94ad8e654d1b337ae762f

playbooks/roles/iptables/tasks/main.yaml

@@ -43,8 +43,7 @@
   vars:
     params:
       files: "{{ distro_lookup_path }}"
-      skip: true
-  loop: "{{ query('first_found', params) }}"
+  loop: "{{ query('first_found', params, errors='ignore') }}"
 
 - name: Enable iptables service
   service: