Make Ctrl+Z undo works when focused on some text field

For example, If I am typing on this search input field:

And I hit `Ctrl+Z`, Smartgit will try to discard changes on some open file instead undo my typing.

I am not focused on something which I can type, it is ok for `Ctrl+Z` to not undo typed text. 

But if I am in an input field, I expect to `Ctrl+Z` to undo text, not discard changes in some random file.