We don't have any jpi files by default

The jenkins role actually explicitly names files as hpi unless they're
jpi.pinned, so make this optional.  It seems to come up more if you've
upgraded plugins via the web UI.

playbooks/roles/tools_jenkins/tasks/main.yml

@@ -16,6 +16,7 @@
 - name: Get the list of jpi files
   shell: "ls {{ jenkins_home }}/plugins/*.jpi"
   register: jpi_files
+  ignore_errors: true
 
 - name: Set the permission on jpi files
   file: 
@@ -24,5 +25,6 @@
     group: "{{ jenkins_group }}"
     mode: 0644
   with_items: jpi_files.stdout_lines
+  when: jpi_files
   notify:
-    - restart Jenkins
\ No newline at end of file
+    - restart Jenkins