Author: Tim Hunt
MDL-41248 completion: fix non-translatable text.
There were two hard-coded strings. Thanks to Guido Hornig for the suggested fix.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=7d3af76e63d09206147e1fd04ce49214c10f7e2a
http://github.com/moodle/moodle/commit/7d3af76e63d09206147e1fd04ce49214c10f7e2a
+ 2.5 en [daysoftotal,core_completion]