[Bug?] Proxy request causes infinite loop

[LostMyCode]

If you add a handler that has proxy option like this

FakeXMLHttpRequest.addHandler({
    url: /projects\/(.*)\/services\/lostmycode/,
    proxy: (url, data) => {
        return "http://localhost:9090/" + url;
    }
});

you will get maximum call stack size exceeded error

Uncaught RangeError: Maximum call stack size exceeded
    at FakeXMLHttpRequest.open

So i think Line#166 should be new window.OriginalXHR() instead of new XMLHttpRequest()

fake-xmlhttprequest/lib/fake-xmlhttprequest.js

Lines 165 to 167 in c4602cf

	if (typeof url === 'string' && url.length > 0) {
	var proxyRequest = new XMLHttpRequest();
	proxyRequest.onreadystatechange = function() {

new window.OriginalXHR() worked for me

@thommyhh Sry for mentioning your old project. It's been 4 or 5 years since the last update, but I just wanted to help to improve this repo coz it really nice and helped me so much. Thank you.