message: Query improvement
diff: @@ -123,9 +123,8 @@ export class CourseController {
  conditions.$or = [];
  if (currentUser.role === 'student') {
  + conditions.active = true;
  conditions.$or.push({students: currentUser._id});
  - conditions.$and = [];
  - conditions.$and.push({active: true});
  } else {
  conditions.$or.push({teachers: currentUser._id});
  conditions.$or.push({courseAdmin: currentUser._id});
  