Properly suppress undefined warning

Although there is no harm in this case, the task in question has a
with_items on a variable that is not set because the previous task did
not run. In this case, it did not run because it's in a block with a
when that did not match - but in the context of a task, when is applied
after with_items and is applied to each with_item, rather than to the
task as a whole. To make the task complete, add a |default() jinja
filter so that the undefined variable is replaced with a defined but
empty value.

Change-Id: I2029b7cac3634a5fe7232f6f823e803e1f4250e6

tasks/main.yml

@@ -24,8 +24,7 @@
       src: "{{ item }}"
       dest: "{{ item }}"
       mode: 0600
-    with_items: hiera_file_paths.paths
-    when: hiera_file_paths is defined
+    with_items: hiera_file_paths.paths|default()
 
   - name: ensure hieradata manifest link is present
     file: