message: fix: don't validate selected model when compareWith is used
  This allows to use [bindValue] and have mixed model like [1, { Name: "bar" })
diff: @@ -570,15 +570,12 @@ export class NgSelectComponent implements OnDestroy, OnChanges, AfterViewInit, C
  }
  private _isValidWriteValue(value: any): boolean {
  - if (!isDefined(value) ||
  - (this.multiple && value === '') ||
  - Array.isArray(value) && value.length === 0
  - ) {
  + if (!isDefined(value) || (this.multiple && value === '') || Array.isArray(value) && value.length === 0) {
  return false;
  }
  const validateBinding = (item: any): boolean => {
  - if (isObject(item) && this.bindValue) {
  + if (!isDefined(this.compareWith) && isObject(item) && this.bindValue) {
  this._console.warn(`Binding object(${JSON.stringify(item)}) with bindValue is not allowed.`);
  return false;
  }
  