Author: Yuliya Bozhko
MDL-43978 badges: Fix lang string
http://git.moodle.org/gw?p=moodle.git;a=commit;h=79405669f93a7339bd84ac09d85c79d9ad412167
http://github.com/moodle/moodle/commit/79405669f93a7339bd84ac09d85c79d9ad412167
+ 2.6 en [error:guestuseraccess,core_badges]