Author: Damyon Wiese
MDL-43334 backup: Lanuage for cancel
Cancel backup buttons need clear lang strings.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=8405e6f1ccc4c055875cef268940e68276fa5749
http://github.com/moodle/moodle/commit/8405e6f1ccc4c055875cef268940e68276fa5749
+ 3.5 en [confirmcancelyes,core_backup]
+ 3.5 en [confirmcancelno,core_backup]