message: solve automerge problem
diff: -<div *ngIf="unitFormService.headline as headline">
  - <strong>{{headline}}</strong>
  -</div>
  -<mat-hint *ngIf="unitFormService.unitInfoText as unitInfoText">
  - <span>{{unitInfoText}}</span>
  -</mat-hint>
  <ng-container [formGroup]="unitForm">
  <mat-form-field >
  <input matInput required formControlName="name" [placeholder]="'common.name'| translate">
  </mat-form-field>
  +
  <mat-form-field >
  <textarea matInput formControlName="description" [placeholder]="'common.description'| translate" rows="4"></textarea>
  </mat-form-field>
  <mat-datepicker-toggle matSuffix [for]="deadlineDatepicker"></mat-datepicker-toggle>
  <mat-datepicker #deadlineDatepicker (selectedChanged)="updateDateTime($event)"></mat-datepicker>
  </mat-form-field>
  +
  <div>
  <mat-slide-toggle formControlName="visible">
  - <span *ngIf="form.value.visible">{{ 'unit.text.canBeSeenByStudents' | translate }}</span>
  - <span *ngIf="!form.value.visible">{{ 'unit.text.canNotBeSeenByStudents' | translate }}</span>
  + <span *ngIf="unitForm.value.visible">{{ 'unit.text.canBeSeenByStudents' | translate }}</span>
  + <span *ngIf="!unitForm.value.visible">{{ 'unit.text.canNotBeSeenByStudents' | translate }}</span>
  </mat-slide-toggle>
  </div>
  </ng-container>
  -
  