I dont see anyway to change that menu,
you can setup up a shutdown menu in the mala layout editor.
When you hit ESC the menu you create (or you can use the default), will allow user to cancel (ESC), or quit mala,
by closing mala, shutdown, or hibernate by pressing 1. These options are set up in mala/options/gui
Here is a pic of what I use on one of my setups: