If the server rejects the attempt to establish a connection by returning
a response status other than 101, then it will not include the
Sec-WebSocket-Accept header. We need to check for 101 status (and return
an appropriate error message) before looking for the accept header.
See #1200
There was not really any "connection failure" with some of these like 404.
They may have body content that is important.
The client should use lws_http_client_http_response(wsi) to discover
the response code the client action received and decide for itself
what to do about that.
