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=ddd7ff18277551ba85ee707942e9aca054b44816
http://github.com/moodle/moodle/commit/ddd7ff18277551ba85ee707942e9aca054b44816
+ 3.6 en [confirmcancelyes,core_backup]
+ 3.6 en [confirmcancelno,core_backup]