Git commits in Moodle 3.10.4 by Dongsheng Cai

commit fdb9a664f69806a07ecc2c669e8a632667cb35d3
Author: Dongsheng Cai <d@tux.im>
Date:   Wed, 14 Apr 2021 20:44:43 +0800
Tag:    v3.10.4

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

commit 8399b45fd06e621bc5576129172aeb3ead6cfe31
Author: Dongsheng Cai <d@tux.im>
Date:   Thu, 08 Apr 2021 20:38:42 +0800
Tag:    v3.10.4

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