Git commits in Moodle 3.9.7 by Dongsheng Cai

commit 737682c7509222d3fec3d5c157684ed6ba833c9b
Author: Dongsheng Cai <d@tux.im>
Date:   Wed, 14 Apr 2021 20:44:43 +0800
Tag:    v3.9.7

MDL-68747 mod_quiz: force LTR for quiz grading overview chart


commit 2410df1fd2d4c0ec2fe31a52b7dfd5e4f80026b8
Author: Dongsheng Cai <d@tux.im>
Date:   Thu, 08 Apr 2021 20:38:42 +0800
Tag:    v3.9.7

MDL-69956 forum: throw exception when advanced grading is not ready