fix client test

"A method call with an unknown request" did not trigger the callback, but it looks like not calling ```HTTPServer#close()``` prevented vows from detecting that.

The reason why this happens in node 0.10/0.11 and not in 0.8 is because of the new streams API that was introduced. In contrast to v0.4-v0.8, the v0.10 stream does not emit 'end' before all data is consumed. Since no data is read, i just got rid of the event listener alltogether and just reply straight on connection for this one.