Changed sudoers task to handle unset variable

tasks/main.yml

@@ -31,7 +31,9 @@
     group: root
     mode: 0440
     validate: /usr/sbin/visudo -cf %s
-  when: ( item.sudo = true )
+  when:
+    - ( item.sudo is defined)
+    - ( item.sudo == true )
   with_items: "{{ human_users }}"
 
 - name: Add user to groups