Git commits in Moodle 3.4.x by dinhloc

commit e2e7f32d6c3c5f9b02ff98656bf5d0a07e1972ce
Author: dinhloc <ndloc1905@gmail.com>
Date:   Tue, 09 Jan 2018 10:38:54 +0800
Tag:    v3.4.3

MDL-61033 quiz: Editing a quiz while a preview is open