chore: Revert unused code

packages/admin-ui/src/lib/core/src/shared/components/channel-assignment-control/channel-assignment-control.component.html

@@ -1,7 +1,7 @@
 <ng-select
     appendTo="body"
     [addTag]="false"
-    [multiple]="true"
+    [multiple]="multiple"
     [ngModel]="value"
     [clearable]="false"
     [searchable]="false"

packages/admin-ui/src/lib/settings/src/components/role-detail/role-detail.component.html

@@ -64,7 +64,6 @@
         <vdr-card [title]="'settings.permissions' | translate">
             <vdr-form-field [label]="'settings.channel' | translate">
                 <vdr-channel-assignment-control
-                    [multiple]="true"
                     formControlName="channelIds"
                     [vdrDisabled]="!('UpdateAdministrator' | hasPermission)"
                 ></vdr-channel-assignment-control>