Adjust NoteBarView to not cause crash

The crash happened in WeSay (https://jira.sil.org/browse/WS-211).
The fix is safe for Windows, and may even be viewed as a bit of an
optimization.
"shouldn't" worries me...I hope you actually tested this?

I have a vague recollection that removing a control from its parent disposes it on Windows, so I'm wondering whether removing it and putting it back will actually work.