message: another bugfix
diff: <mat-header-row *matHeaderRowDef="displayedColumns"></mat-header-row>
  <mat-row *matRowDef="let row; columns: displayedColumns;"></mat-row>
  </mat-table>
  -<button mat-raised-button color="primary" class="mat-button saveButton" (click)="saveNotificationSettings()">{{ common.save | translate }}</button>
  +<button mat-raised-button color="primary" class="mat-button saveButton" (click)="saveNotificationSettings()">{{ 'common.save' | translate }}</button>
  