Git commits in Moodle 3.8.x by Colin Campbell

commit b4779307a2dc65a12c17205dbbc7e43efc2b99f7
Author: Colin Campbell <colin@umn.edu>
Date:   Thu, 10 Oct 2019 09:38:25 +0800
Tag:    v3.8.2

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