Update vendor files to point to kubernetes-1.12.0-beta.1

vendor/k8s.io/apimachinery/pkg/util/net/http.go

@@ -91,7 +91,8 @@ func SetOldTransportDefaults(t *http.Transport) *http.Transport {
 		// ProxierWithNoProxyCIDR allows CIDR rules in NO_PROXY
 		t.Proxy = NewProxierWithNoProxyCIDR(http.ProxyFromEnvironment)
 	}
-	if t.DialContext == nil {
+	// If no custom dialer is set, use the default context dialer
+	if t.DialContext == nil && t.Dial == nil {
 		t.DialContext = defaultTransport.DialContext
 	}
 	if t.TLSHandshakeTimeout == 0 {
@@ -129,7 +130,18 @@ func DialerFor(transport http.RoundTripper) (DialFunc, error) {
 
 	switch transport := transport.(type) {
 	case *http.Transport:
-		return transport.DialContext, nil
+		// transport.DialContext takes precedence over transport.Dial
+		if transport.DialContext != nil {
+			return transport.DialContext, nil
+		}
+		// adapt transport.Dial to the DialWithContext signature
+		if transport.Dial != nil {
+			return func(ctx context.Context, net, addr string) (net.Conn, error) {
+				return transport.Dial(net, addr)
+			}, nil
+		}
+		// otherwise return nil
+		return nil, nil
 	case RoundTripperWrapper:
 		return DialerFor(transport.WrappedRoundTripper())
 	default:
@@ -167,10 +179,8 @@ func FormatURL(scheme string, host string, port int, path string) *url.URL {
 }
 
 func GetHTTPClient(req *http.Request) string {
-	if userAgent, ok := req.Header["User-Agent"]; ok {
-		if len(userAgent) > 0 {
-			return userAgent[0]
-		}
+	if ua := req.UserAgent(); len(ua) != 0 {
+		return ua
 	}
 	return "unknown"
 }