Git commits in Moodle 3.4.0 by Matt Petro

commit f5ea99bf6edee0ef9fb85b91976679298af905e1
Author: Matt Petro <matt.petro@wisc.edu>
Date:   Thu, 14 Sep 2017 22:39:09 +0800
Tag:    v3.4.0-beta

MDL-60121 enrol: Fix enrol plugin backup