message: API: Check /api/duplicate/lecture/:id course auth
diff: @@ -102,6 +102,10 @@ export class DuplicationController {
  async duplicateLecture(@Param('id') id: string,
  @BodyParam('courseId', {required: true}) targetCourseId: string,
  @CurrentUser() currentUser: IUser) {
  + const course = await Course.findOne({lectures: id});
  + if (!course.checkPrivileges(currentUser).userCanEditCourse) {
  + throw new ForbiddenError();
  + }
  const targetCourse = await Course.findById(targetCourseId);
  if (!targetCourse.checkPrivileges(currentUser).userCanEditCourse) {
  throw new ForbiddenError();
  