message: fix: load items from ng-option async
  fixes
diff: @@ -197,7 +197,7 @@ export class NgSelectComponent implements OnDestroy, OnChanges, AfterViewInit, C
  }
  ngAfterViewInit() {
  - if (this.ngOptions.length > 0 && this.items.length === 0) {
  + if (this.items && this.items.length === 0) {
  this._setItemsFromNgOptions();
  }
  }
  