There no way to solve it. You only can close app was cliking "X" icon on top-right from window.
I told to Scirra to add Oficial Node-Webkit plugin to access Node-Webkit API, but i got no official response.
However, if you really need faster, you should download this plugin http://www.scirra.com/forum/topic60647.html
It's old, but still working, there a problem you shouldn't use export node-webkit because it won't work, otherwise you should export HTML5 version and you could compile with node-webkit SDK following this tutorialhttps://www.scirra.com/tutorials/417/exporting-to-exe-using-node-webkit