add missing import

alfa-client/libs/vorgang-detail/src/lib/vorgang-detail.module.ts

@@ -58,7 +58,7 @@ import { ReactiveFormsModule } from '@angular/forms';
 import { MatDialogActions, MatDialogContent } from '@angular/material/dialog';
 import { MatIcon } from '@angular/material/icon';
 import { MatMenuTrigger } from '@angular/material/menu';
-import { MatTab, MatTabGroup } from '@angular/material/tabs';
+import { MatTab, MatTabContent, MatTabGroup } from '@angular/material/tabs';
 import { RouterModule, Routes } from '@angular/router';
 import {
   ButtonWithSpinnerComponent,
@@ -234,6 +234,7 @@ const routes: Routes = [
     TooltipDirective,
     EditIconComponent,
     DiscardVorgangIconComponent,
+    MatTabContent,
   ],
   declarations: [
     VorgangDetailPageComponent,