Author: Shamim Rezaie
MDL-62231 block_recent_activity: Implement null provider for the block
http://git.moodle.org/gw?p=moodle.git;a=commit;h=75dc5bf14b965887c9f702e0758ec584d8ae6da6
http://github.com/moodle/moodle/commit/75dc5bf14b965887c9f702e0758ec584d8ae6da6
+ 3.4 en [privacy:metadata,block_recent_activity]