Author: Ankit Agarwal
MDL-42890 backups: Updated help string to indicate logging is required
http://git.moodle.org/gw?p=moodle.git;a=commit;h=2f4cf9a1daa5143f0a8002fa011889645fdd08ce
http://github.com/moodle/moodle/commit/2f4cf9a1daa5143f0a8002fa011889645fdd08ce
+ 2.7 en [skipmodifprevhelp,core_backup]