Update oxy dependency

vendor/github.com/vulcand/oxy/utils/handler.go

@@ -1,22 +1,34 @@
 package utils
 
 import (
+	"context"
 	"io"
 	"net"
 	"net/http"
+
+	log "github.com/sirupsen/logrus"
 )
 
+// StatusClientClosedRequest non-standard HTTP status code for client disconnection
+const StatusClientClosedRequest = 499
+
+// StatusClientClosedRequestText non-standard HTTP status for client disconnection
+const StatusClientClosedRequestText = "Client Closed Request"
+
+// ErrorHandler error handler
 type ErrorHandler interface {
 	ServeHTTP(w http.ResponseWriter, req *http.Request, err error)
 }
 
+// DefaultHandler default error handler
 var DefaultHandler ErrorHandler = &StdHandler{}
 
-type StdHandler struct {
-}
+// StdHandler Standard error handler
+type StdHandler struct{}
 
 func (e *StdHandler) ServeHTTP(w http.ResponseWriter, req *http.Request, err error) {
 	statusCode := http.StatusInternalServerError
+
 	if e, ok := err.(net.Error); ok {
 		if e.Timeout() {
 			statusCode = http.StatusGatewayTimeout
@@ -25,11 +37,23 @@ func (e *StdHandler) ServeHTTP(w http.ResponseWriter, req *http.Request, err err
 		}
 	} else if err == io.EOF {
 		statusCode = http.StatusBadGateway
+	} else if err == context.Canceled {
+		statusCode = StatusClientClosedRequest
 	}
+
 	w.WriteHeader(statusCode)
-	w.Write([]byte(http.StatusText(statusCode)))
+	w.Write([]byte(statusText(statusCode)))
+	log.Debugf("'%d %s' caused by: %v", statusCode, statusText(statusCode), err)
 }
 
+func statusText(statusCode int) string {
+	if statusCode == StatusClientClosedRequest {
+		return StatusClientClosedRequestText
+	}
+	return http.StatusText(statusCode)
+}
+
+// ErrorHandlerFunc error handler function type
 type ErrorHandlerFunc func(http.ResponseWriter, *http.Request, error)
 
 // ServeHTTP calls f(w, r).