common: Scheduled removal of old backups at 0:30

So for the most time two states are stored on the server.
The storage which will stay free can be better used to calculate the
storage which can still be used by dividing the free storage by 3.

roles/common/tasks/helpers.yml

@@ -33,8 +33,8 @@
 
 - name: Configure auto remove older backups
   cron:
-    hour: 1
-    minute: 55
+    hour: 0
+    minute: 30
     job: "{{ global_helper_directory }}/backup_autoremove.sh"
     name: "Auto remove older backups"
     state: present