update qpack to v0.2.0

http3/server_test.go

@@ -210,7 +210,7 @@ var _ = Describe("Server", func() {
 			})
 
 			It("errors when the client sends a too large header frame", func() {
-				s.Server.MaxHeaderBytes = 42
+				s.Server.MaxHeaderBytes = 20
 				s.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 					Fail("Handler should not be called.")
 				})
@@ -274,7 +274,9 @@ var _ = Describe("Server", func() {
 					close(handlerCalled)
 				})
 
-				url := bytes.Repeat([]byte{'a'}, http.DefaultMaxHeaderBytes+1)
+				// use 2*DefaultMaxHeaderBytes here. qpack will compress the requiest,
+				// but the request will still end up larger than DefaultMaxHeaderBytes.
+				url := bytes.Repeat([]byte{'a'}, http.DefaultMaxHeaderBytes*2)
 				req, err := http.NewRequest(http.MethodGet, "https://"+string(url), nil)
 				Expect(err).ToNot(HaveOccurred())
 				setRequest(encodeRequest(req))