Force HTTP response header casing to WWW-Authenticate

This change forces the `WWW-Authenticate` casing for the default HTTP response header on the HTTP/HTTPS honeypot servers. Previously, Go automatically converted it to `Www-Authenticate`. This update matches the casing used by most other web servers. The change is intended to reduce the risk of fingerprinting the honeypot server by making it behave more like a typical web server.

internal/httpserver/httpserver.go

@@ -175,7 +175,7 @@ func handleConnection(cfg *config.Server, customHeaders map[string]string) http.
 			} else {
 				// Serve the default page that prompts the client for basic
 				// authentication.
-				w.Header().Set("WWW-Authenticate", "Basic")
+				w.Header()["WWW-Authenticate"] = []string{"Basic"}
 				w.WriteHeader(http.StatusUnauthorized)
 			}
 		} else {