[Windows] Remove the default binding between buffer-zoom and Alt+0

[Pavel Sanda]

On Fri, Jan 15, 2021 at 02:00:10AM +0100, Thibaut Cuvelier wrote:
> I would propose to change the default binding to Ctrl+0, as it's more
> common (although not ubiquitous), and this would fix the problem of
> changing zoom when you try to insert a character.
> 
> What do you think of this?

Looks reasonable. Pavel