[MDL-8407] [MDL-14129] Fix little typo in error message 'invalidcourseid'. This error message will  be used for solving MDL-8407. Same message has already been committed to MOODLE_19_STABLE.
[MDL-8407] [MDL-14129] Fix little typo in error message 'invalidcourseid'. This error message will  be used for solving MDL-8407. Same message has already been committed to MOODLE_19_STABLE.

dilawar/moodle