fix(web-server): strip scheme, host and port

Absolute URI requests are striped to match files in middlewares.
AbsoluteURIs are use from proxies according to [Section
5.1.2](http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html)

PR to LearnBoost/socket.io#1304 is needed to fully resolve this issue
karma-runner/karma#705