gRPC migration update

Change-Id: Icdd1a824948fa994cd36bd121c962f5ecf74e3cf
diff --git a/vendor/golang.org/x/net/http2/flow.go b/vendor/golang.org/x/net/http2/flow.go
index cea601f..b51f0e0 100644
--- a/vendor/golang.org/x/net/http2/flow.go
+++ b/vendor/golang.org/x/net/http2/flow.go
@@ -8,6 +8,8 @@
 
 // flow is the flow control window's size.
 type flow struct {
+	_ incomparable
+
 	// n is the number of DATA bytes we're allowed to send.
 	// A flow is kept both on a conn and a per-stream.
 	n int32