Git commits in Moodle 3.8.x by hiendinh

commit 5f6ce419c4b1a3b49ffc61208fda1c502d5f8612
Author: hiendinh <hdpv2@open.ac.uk>
Date:   Tue, 02 Jun 2020 12:22:52 +0800
Tag:    v3.8.4

MDL-68890 progressbar: prevent display exist file's progress bar


commit 4a77582d1694d457b451a186df5d20f9a194b21d
Author: hiendinh <hdpv2@open.ac.uk>
Date:   Thu, 28 May 2020 16:32:46 +0800
Tag:    v3.8.4

MDL-68841 Modal dialogs: Wrong behavior of popup