Author: Rossiani Wijaya
Backport MDL-29872 to 21_STABLE
http://git.moodle.org/gw?p=moodle.git;a=commit;h=c62a20c42b96f0195c4de075e5c58a4e7d381428
http://github.com/moodle/moodle/commit/c62a20c42b96f0195c4de075e5c58a4e7d381428
+ 2.1 en [logoutdesc,repository_dropbox]