added timestamp_to_user to created_at to get more obsolete container images deleted.
added timestamp_to_user to created_at to get more obsolete container
images deleted.

jens-maus/RaspberryMatic,jens-maus/RaspberryMatic,jens-maus/RaspberryMatic,jens-maus/RaspberryMatic,jens-maus/RaspberryMatic,jens-maus/RaspberryMatic