Initialize registry_namespaces unconditionally if not initialized

The deploy-env playbook can fail with an error stating that
registry_namespaces is not defined in some cases. This change moves
the initialization of registry_namespaces so that buildset_registry
is not required for it to be set when other conditions are not met.

Change-Id: I160e7d479008fd3afd460382691673b92bd042c9

roles/deploy-env/tasks/containerd.yaml

@@ -80,6 +80,11 @@
         skip_verify: true
   when: registry_mirror is defined
 
+- name: Init registry_namespaces if not defined
+  set_fact:
+    registry_namespaces: "[]"
+  when: not registry_namespaces is defined
+
 - name: Buildset registry namespace
   when: buildset_registry is defined
   block:
@@ -106,11 +111,6 @@
           ca: "/usr/local/share/ca-certificates/{{ buildset_registry_alias }}.crt"
           auth: "{{ (buildset_registry.username + ':' + buildset_registry.password) | b64encode }}"
 
-    - name: Init registry_namespaces if not defined
-      set_fact:
-        registry_namespaces: "[]"
-      when: not registry_namespaces is defined
-
     - name: Append buildset_registry to registry namespaces
       when:
         - buildset_registry_namespace is defined