message: fix(dropdown): prevent ng router active link double ngOnInit issue
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diff: @@ -109,6 +109,7 @@ export class BsDropdownDirective implements OnInit, OnDestroy {
  private _isDisabled: boolean;
  private _dropdown: ComponentLoader<BsDropdownContainerComponent>;
  private _subscriptions: Subscription[] = [];
  + private _isInited = false;
  constructor(private _elementRef: ElementRef,
  private _renderer: Renderer,
  @@ -129,6 +130,12 @@ export class BsDropdownDirective implements OnInit, OnDestroy {
  }
  ngOnInit(): void {
  + // fix: seems there are an issue with `routerLinkActive`
  + // which result in duplicated call ngOnInit without call to ngOnDestroy
  + // read more: https://github.com/valor-software/ngx-bootstrap/issues/1885
  + if (this._isInited) {return;}
  + this._isInited = true;
  +
  this._showInline = !this.container;
  // attach DOM listeners
  