Git commits in Moodle 3.4.6 by Dan Marsden

commit 2ac7cdf32afd898874fbf5a47188f36a6559ff74
Author: Dan Marsden <dan@danmarsden.com>
Date:   Tue, 06 Nov 2018 04:57:36 +0800
Tag:    v3.4.6

MDL-63800 mod_assign: don't show grade if not set.