Author: Tim Hunt
MDL-37599 question import: add missing string.
AMOS BEGIN
MOV [matcherror,question],[invalidgrade,question]
AMOS END
http://git.moodle.org/gw?p=moodle.git;a=commit;h=b5d09003bbe6c0a4759bc2ca30557a948af939c8
http://github.com/moodle/moodle/commit/b5d09003bbe6c0a4759bc2ca30557a948af939c8
+ 2.5 en [invalidgrade,core_question]
- 2.5 en [matcherror,core_question]