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=d6b5be41d4b59e4ea3605fee974f7767900babea
http://github.com/moodle/moodle/commit/d6b5be41d4b59e4ea3605fee974f7767900babea
+ 3.3 en [privacy:metadata,block_recent_activity]