Author: viettruongq
MDL-70760 admin: Limited length config setting validate client-side
http://git.moodle.org/gw?p=moodle.git;a=commit;h=2375b00a085f92f6252e8b045cdb235f9c275c1d
http://github.com/moodle/moodle/commit/2375b00a085f92f6252e8b045cdb235f9c275c1d
+ 4.4 en [maxcharacter,core_admin]