Author: Andrew Nicols
MDL-62370 core_privacy: Directory-less subsystems are compliant
http://git.moodle.org/gw?p=moodle.git;a=commit;h=d334974409495785ee98761578f9fdbe0af88856
http://github.com/moodle/moodle/commit/d334974409495785ee98761578f9fdbe0af88856
+ 3.3 en [privacy:subsystem:empty,privacy]