Set http.Server.ErrorLog to a logWriter that routes HTTP server errors
(TLS handshake failures, malformed requests) to the GOST logger at Debug
level instead of escaping to stderr via log.Printf.
Without this, network scanners and protocol filters probing the WSS port
produce uncontrolled output:
http: TLS handshake error from ...
Also downgrade WebSocket upgrade failures from Error to Warn — plain HTTP
requests hitting the WebSocket endpoint are operational noise.
Fixesgo-gost/gost#419