Git commits in Moodle 3.1.9 by Sara Arjona

commit 54bb01439e84da58fb97ccf673eaca49b9c47ba6
Author: Sara Arjona <sara@moodle.com>
Date:   Mon, 30 Oct 2017 15:30:11 +0800
Tag:    v3.1.9

MDL-60550 user: Add more restrictions in keyword searches