fix standalone

src/app/widget-modules/components/add-song/add-song.component.html

@@ -3,14 +3,9 @@
     <mat-label>Lied hinzufügen...</mat-label>
     <mat-select (selectionChange)="onAddSongSelectionChanged($event)">
       <mat-option>
-        <ngx-mat-select-search
-          [formControl]="filteredSongsControl"
-        ></ngx-mat-select-search>
-      </mat-option>
-      <mat-option *ngFor="let song of filteredSongs()" [value]="song.id">{{
-          song.title
-        }}
+        <ngx-mat-select-search [formControl]="filteredSongsControl"></ngx-mat-select-search>
       </mat-option>
+      <mat-option *ngFor="let song of filteredSongs()" [value]="song.id">{{ song.title }}</mat-option>
     </mat-select>
   </mat-form-field>
 </div>