Author: Safat Shahin
MDL-73350 qbank_statistics: Discrimination index column update
This implementation changes a little logic where the
discrimination index shows an empty row if there is
no attempts been made to a question rather than showing
very likely.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=750fafeedd3bb8f96f5d80f0ee50f6e4bab701b7
http://github.com/moodle/moodle/commit/750fafeedd3bb8f96f5d80f0ee50f6e4bab701b7
+ 4.0 en [emptyvalue,qbank_statistics]