Git commits in Moodle 3.9.0 by Colin Campbell

commit eeca35e4ad946382e82e16b6f4d757ffae9d5c62
Author: Colin Campbell <colin@umn.edu>
Date:   Thu, 10 Oct 2019 09:38:25 +0800
Tag:    v3.9.0-beta

MDL-52189 file: skip deleting temp files that appear during cleanup