Git commits in Moodle 3.5.0 by Julien Boulen

commit 6c519fe4d7586ef41ee7acddb207d29c4512485c
Author: Julien Boulen <julien.boulen@univ-rennes2.fr>
Date:   Fri, 15 Dec 2017 16:36:04 +0800
Tag:    v3.5.0-beta

MDL-60036 block_online_users: complete string about online users