Author: Marina Glancy
MDL-54769 backup: add missing error language string
http://git.moodle.org/gw?p=moodle.git;a=commit;h=88038050b14d166a854b4906152d4d7796b411c8
http://github.com/moodle/moodle/commit/88038050b14d166a854b4906152d4d7796b411c8
+ 3.2 en [error_question_answers_missing_in_db,core_error]