several issues with tab replacement

[fcnjd]

Steps to reproduce:

1. Open a text editor, I used NPP but most should do
2. Paste the following:

	Callable

3. Go to Brailleessentials settings and enable replace tabs by spaces
4. Popup correctly appears to restart NVDA, accept
   Following notes:

• Tab sign is still shown, until I start selecting any character in the word using shift+right, then the replacement magically drops in - on the next cursor move tab comes back
• Try to increase or decrease the number of spaces being used - it has no effect, 2 are always used
• Deactivate the setting again, now the popup to restart NVDA doesn't come although it would be needed, as replacement still triggers when selecting characters until an NVDA restart