Git commits in Moodle 3.5.5 by Eric Merrill

commit 85fec2b60535734bb7a622c15108a489f29458bb
Author: Eric Merrill <merrill@oakland.edu>
Date:   Wed, 23 Jan 2019 10:40:12 +0800
Tag:    v3.5.5

MDL-64609 gradebook: Prevent infinite loop in regrading