FIX: Do not call 'set' in destroyed directory table component (PR #13567)

If you go wild and toggle directory columns like crazy you can trigger functions after the component has been destroyed. Nothing breaks in the UI but you can get a couple JS errors because set is being called on a destroyed component.

GitHub

You could also throw in this.isDestroying || like we do in most places.

@CvX Good call. added.