Author: Dani Palou
MDL-67907 airnotifier: Warn if some settings disabled after get key
http://git.moodle.org/gw?p=moodle.git;a=commit;h=fbe3178a558e380ab54eb0f7f7b74822492aea64
http://github.com/moodle/moodle/commit/fbe3178a558e380ab54eb0f7f7b74822492aea64
+ 3.9 en [enableprocessor,message_airnotifier]