100% CPU bug with uws and webkitgtk module

When a non-interfering webkitgtk instance is created upon request, and a socket.io server is running with uws, and a client has a socket.io connection open to the server, closing the client's web page makes the Node.js server run at 100% CPU.

It does not depend on the web browser used as client, and the webkitgtk instance does nothing besides just being created with a about:blank page.

The webkitgtk module maintains a very simple timeout-based event loop, to be able to run gtk events loop without interfering with the uv events loop. Nothing clever here.