message: added missing type = reset
diff: </mat-form-field>
  <br/>
  <button mat-raised-button color="primary" class="mat-button" type="submit">{{ 'dashboard.addCourse' | translate }}</button>
  - <button class="mat-button" color="secondary" (click)="close()">Cancel</button>
  + <button class="mat-button" color="secondary" (click)="close()" type="reset">Cancel</button>
  </form>
  </div>
  </mat-dialog-content>
  