Developer credits
Git commits in Moodle 3.3.0 by Matt Davidson
commit 6be2b79b9c0f06aa46ebe7bcbef06ec11c5db7c7 Author: Matt Davidson <davidso1@rose-hulman.edu> Date: Mon, 12 Dec 2016 21:22:51 +0800 Tag: v3.3.0-beta MDL-56810 unoconv: task fails if user removed