Author: jerome mouneyrac
webservice MDL-23438 do not create a token for a user if the service doesn't allow him
http://git.moodle.org/gw?p=moodle.git;a=commit;h=a44460b5ef6be6f10ff2465b53aa57c9a4ffd138
http://github.com/moodle/moodle/commit/a44460b5ef6be6f10ff2465b53aa57c9a4ffd138
+ 2.0 en [usernotallowed,core_webservice]