Fix warning with Ansible 2.5

tasks/packages.yml

@@ -13,7 +13,7 @@
     name: "{{ item }}"
     state: latest
   with_items: "{{ monitored_packages_np }}"
-  when: monitoringplugins|failed
+  when: monitoringplugins is failed
 
 
 - name: Instal additional packages