message: fix: ignore tab when dropdown is closed and addTag is false
  closes
diff: @@ -752,9 +752,10 @@ export class NgSelectComponent implements OnDestroy, OnChanges, AfterViewInit, C
  }
  private _handleTab($event: KeyboardEvent) {
  - if (this.isOpen === false && !isDefined(this.addTag)) {
  + if (this.isOpen === false && !this.addTag) {
  return;
  }
  +
  if (this.selectOnTab) {
  if (this.itemsList.markedItem) {
  this.toggleItem(this.itemsList.markedItem);
  