Git commits in Moodle 3.4.x by Ed Basset

commit 6f5ae7edade6b8b0eda6c4781c51f8d5a39e9991
Author: Ed Basset <ed.a.bassett@gmail.com>
Date:   Mon, 21 May 2018 18:15:26 +0800
Tag:    v3.4.4

MDL-36424 wiki: set group so subwiki tabs/pages display correctly