Git commits in Moodle 3.5.4 by Tomasz Muras

commit 9d8470e4b809c5daf5e94ba5703c52b124afb9c1
Author: Tomasz Muras <tm@enovation.ie>
Date:   Tue, 17 Jul 2018 21:37:15 +0800
Tag:    v3.5.4

MDL-52966 core: static cache fix for file types.