Git commits in Moodle 3.9.0 by Nathan Nguyen

commit a9c139c8d43bb682fd463797c2831db7a68d4fec
Author: Nathan Nguyen <nathannguyen@catalyst-au.net>
Date:   Fri, 17 Apr 2020 11:10:26 +0800
Tag:    v3.9.0-beta

MDL-39571 repository_recent: query improvement

commit 1529fc7954b8eba8fce5fda6aadd7a4651b200e4
Author: Nathan Nguyen <nathannguyen@catalyst-au.net>
Date:   Fri, 17 Apr 2020 11:08:22 +0800
Tag:    v3.9.0-beta

MDL-39571 repository_recent: add unit test

commit 464bd7ecd5eda966d5328c88d313fad7498b635a
Author: Nathan Nguyen <nathannguyen@catalyst-au.net>
Date:   Mon, 24 Feb 2020 06:40:57 +0800
Tag:    v3.9.0-beta

MDL-67504 antivirus_clamav: Add scanning tries option