Author: Mark Nelson
MDL-55638 core_message: add message when there are no contacts
http://git.moodle.org/gw?p=moodle.git;a=commit;h=4d1b76ee36e6430aab7227952365719e2030c2c0
http://github.com/moodle/moodle/commit/4d1b76ee36e6430aab7227952365719e2030c2c0
+ 3.2 en [nocontacts,core_message]
+ 3.2 en [noconversations,core_message]