change golang.org/x/net to be the same revision as used in kubernetes

vendor/golang.org/x/net/http2/write.go

@@ -10,9 +10,10 @@ import (
 	"log"
 	"net/http"
 	"net/url"
+	"time"
 
-	"golang.org/x/net/http/httpguts"
 	"golang.org/x/net/http2/hpack"
+	"golang.org/x/net/lex/httplex"
 )
 
 // writeFramer is implemented by any type that is used to write frames.
@@ -89,7 +90,11 @@ type writeGoAway struct {
 
 func (p *writeGoAway) writeFrame(ctx writeContext) error {
 	err := ctx.Framer().WriteGoAway(p.maxStreamID, p.code, nil)
-	ctx.Flush() // ignore error: we're hanging up on them anyway
+	if p.code != 0 {
+		ctx.Flush() // ignore error: we're hanging up on them anyway
+		time.Sleep(50 * time.Millisecond)
+		ctx.CloseConn()
+	}
 	return err
 }
 
@@ -186,7 +191,6 @@ type writeResHeaders struct {
 	date          string
 	contentType   string
 	contentLength string
-	noSniff       bool
 }
 
 func encKV(enc *hpack.Encoder, k, v string) {
@@ -223,9 +227,6 @@ func (w *writeResHeaders) writeFrame(ctx writeContext) error {
 	if w.contentLength != "" {
 		encKV(enc, "content-length", w.contentLength)
 	}
-	if w.noSniff {
-		encKV(enc, "x-content-type-options", "nosniff")
-	}
 	if w.date != "" {
 		encKV(enc, "date", w.date)
 	}
@@ -354,7 +355,7 @@ func encodeHeaders(enc *hpack.Encoder, h http.Header, keys []string) {
 		}
 		isTE := k == "transfer-encoding"
 		for _, v := range vv {
-			if !httpguts.ValidHeaderFieldValue(v) {
+			if !httplex.ValidHeaderFieldValue(v) {
 				// TODO: return an error? golang.org/issue/14048
 				// For now just omit it.
 				continue