Author: Damyon Wiese
MDL-36804 Assign submission history - One language string change.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=3a9dc7f22fd6dfc6a79bab8126c4f2fcc3e906cf
http://github.com/moodle/moodle/commit/3a9dc7f22fd6dfc6a79bab8126c4f2fcc3e906cf
+ 2.5 en [attemptheading,mod_assign]