Author: Marina Glancy
MDL-49003 login: prevent signup when user is logged in
http://git.moodle.org/gw?p=moodle.git;a=commit;h=7a6581f6c2a17fcbcf4362c04c868521b02c7526
http://github.com/moodle/moodle/commit/7a6581f6c2a17fcbcf4362c04c868521b02c7526
+ 2.7 en [cannotsignup,core_error]