fix typo in on_url function

[vtjnash]

i don't know what this function does or how to test it, but this was my best guess on how it should look

[Keno]

I believe this function is never actually called.

[vtjnash]

good call. it can't be called: https://nodejs.org/dist/latest-v5.x/docs/api/http.html#http_message_url

i've updated to just remove it

[malmaud]

Thanks, gentlemen.