Author: Zig Tan
MDL-61568 repository_s3: Implement null privacy provider
http://git.moodle.org/gw?p=moodle.git;a=commit;h=013149f1a2bfeb8929675bdf68ddde73ef85a607
http://github.com/moodle/moodle/commit/013149f1a2bfeb8929675bdf68ddde73ef85a607
+ 3.5 en [privacy:metadata,repository_s3]