use the correct QUIC version in the Chrome integration tests

Because the version variable was set in the loop, we would always start
a QUIC server with the lowest support QUIC version.

integrationtests/chrome/chrome_suite_test.go

@@ -34,7 +34,6 @@ const (
 var (
 	nFilesUploaded int32 // should be used atomically
 	doneCalled     utils.AtomicBool
-	version        protocol.VersionNumber
 )
 
 func TestChrome(t *testing.T) {
@@ -83,10 +82,6 @@ func init() {
 	})
 }
 
-var _ = JustBeforeEach(func() {
-	testserver.StartQuicServer([]protocol.VersionNumber{version})
-})
-
 var _ = AfterEach(func() {
 	testserver.StopQuicServer()