message: API: checkPrivileges of /api/export/unit/:id
diff: @@ -99,8 +99,12 @@ export class ExportController {
  * }
  */
  @Get('/unit/:id')
  - async exportUnit(@Param('id') id: string) {
  + async exportUnit(@Param('id') id: string, @CurrentUser() currentUser: IUser) {
  const unit = await Unit.findById(id);
  + const course = await Course.findById(unit._course);
  + if (!course.checkPrivileges(currentUser).userCanEditCourse) {
  + throw new ForbiddenError();
  + }
  return unit.exportJSON();
  }
  