transmit http answer code using http_client

The http answer code is available through uri filed of mg_connection however this is not explicit.
I propose this workaround to stackoverflow answer http://stackoverflow.com/a/26316402/3102264.
So I propose this fix in order to provide status_code in a more explicit way.
Could you follow Google style please,

    if () {
      ...
    } else {
       ...
    }