Fix CI : Change nothing if nothing needs to be done.

roles/postfix/tasks/main.yml

@@ -28,6 +28,7 @@
 
 - name: Generate postmaps
   command: /usr/sbin/postmap {{ item }}
+  when: item | changed
   loop:
     - /etc/postfix/canonical
     - /etc/postfix/mime_header_checks

upgrade.yml

@@ -33,6 +33,8 @@
         # occ return code is 3 when ownCloud is already latest version
         - upgrade_owncloud.rc != 0
         - upgrade_owncloud.rc != 3
+      changed_when:
+        - upgrade_owncloud.rc != 3
 
     - name: Upgrade owncloud output
       debug: