added userstory dropdown

src/app/task-form/task-form.component.html

@@ -8,8 +8,8 @@
                 <h6 class="modal-caption text-muted"> Gehört zu Story: <a href="#" id="userstoryTitle">{{this.userstoryId}}</a></h6>
             </tr>
             <select class="form-control custom-select mr-sm-2" id="prio" required name="prio"
-            [(ngModel)]="task.priority" *ngFor="let userstory of userstories">
-              <option value="low">{{userstory}}</option>
+            [(ngModel)]="task.priority">
+              <option *ngFor="let userstory of userstories" value="low">{{userstory.title}}</option>
             </select>
         </table>
         <button (click)="onClose()" type="button" class="close" aria-label="Close">