vendor: update grpc dependencies

Signed-off-by: Stephen J Day <stephen.day@docker.com>

vendor/google.golang.org/grpc/credentials/credentials.go

@@ -102,6 +102,10 @@ type TransportCredentials interface {
 	// authentication protocol on rawConn for clients. It returns the authenticated
 	// connection and the corresponding auth information about the connection.
 	// Implementations must use the provided context to implement timely cancellation.
+	// gRPC will try to reconnect if the error returned is a temporary error
+	// (io.EOF, context.DeadlineExceeded or err.Temporary() == true).
+	// If the returned error is a wrapper error, implementations should make sure that
+	// the error implements Temporary() to have the correct retry behaviors.
 	ClientHandshake(context.Context, string, net.Conn) (net.Conn, AuthInfo, error)
 	// ServerHandshake does the authentication handshake for servers. It returns
 	// the authenticated connection and the corresponding auth information about
@@ -165,9 +169,7 @@ func (c *tlsCreds) ClientHandshake(ctx context.Context, addr string, rawConn net
 	case <-ctx.Done():
 		return nil, nil, ctx.Err()
 	}
-	// TODO(zhaoq): Omit the auth info for client now. It is more for
-	// information than anything else.
-	return conn, nil, nil
+	return conn, TLSInfo{conn.ConnectionState()}, nil
 }
 
 func (c *tlsCreds) ServerHandshake(rawConn net.Conn) (net.Conn, AuthInfo, error) {