How to reproduce:
- a group owner with no author rights
- the group is assigned to a course
- group owner opens the group --> administration –> courses
- click 'Add courses'
- NOK: the group coach has buttons to create or import new courses, although having no author rights (and therefore will never see these courses)
- OK: the group owner can only add courses from the table; the table only shows courses of which he/she is the owner