Revert "enable readv reader on windows"

This reverts commit 4bd1ef0650ccaeb69e67e660769a35ce6d7ce942.

common/buf/readv_reader.go

@@ -142,7 +142,7 @@ func init() {
 	value := platform.NewEnvFlag("v2ray.buf.readv").GetValue(func() string { return defaultFlagValue })
 	switch value {
 	case defaultFlagValue, "auto":
-		if (runtime.GOARCH == "386" || runtime.GOARCH == "amd64" || runtime.GOARCH == "s390x") && (runtime.GOOS == "linux" || runtime.GOOS == "darwin" || runtime.GOOS == "windows") {
+		if (runtime.GOARCH == "386" || runtime.GOARCH == "amd64" || runtime.GOARCH == "s390x") && (runtime.GOOS == "linux" || runtime.GOOS == "darwin") {
 			useReadv = true
 		}
 	case "enable":