message: Work for fix dropdown controlEmpty class condition
diff: @@ -125,7 +125,7 @@ export class QuestionDropdownModel extends QuestionSelectBase {
  this.isEmpty();
  return new CssClassBuilder()
  .append(this.cssClasses.control)
  - .append(this.cssClasses.controlEmpty, !this.isEmpty())
  + .append(this.cssClasses.controlEmpty, this.isEmpty())
  .append(this.cssClasses.onError, this.errors.length > 0)
  .append(this.cssClasses.controlDisabled, this.isReadOnly)
  .toString();
  