README examples has wrong listening port numbers

[subomi]

In section Setup a stand-alone proxy server with custom server logic:
We have:
`var server = http.createServer(function(req, res) {
// You can define here your custom logic to handle the request
// and then proxy the request.
proxy.web(req, res, { target: 'http://127.0.0.1:5060' });
});

console.log("listening on port 5050")
server.listen(5050);`

Instead of:
`var server = http.createServer(function(req, res) {
// You can define here your custom logic to handle the request
// and then proxy the request.
proxy.web(req, res, { target: 'http://127.0.0.1:5050' });
});

console.log("listening on port 5050")
server.listen(5050)'

And also the same thing in section Setup a stand-alone proxy server with proxy request header re-writing

[indexzero]

Fixed in #970