@Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        if (msg instanceof HttpRequest req) {
            

            for (String name : req.headers().names()) {
                if (name.startsWith("x-http2-")) {
                    req.headers().remove(name);
                }
            }
        }

        super.channelRead(ctx, msg);
    }
The Http2ServerDowngrader currently is always incorrectly setting the "x-http2-stream-id"
header to "0", which is confusing. And as we don't actually need it and the other "x-http2-" headers, we
strip them out here to avoid the confusion.

Hopefully in a future netty release that header value will be correct and we can then
stop doing this. Although potentially we _never_ want to pass these downstream to origins .... ?
zuul-core/src/main/java/com/netflix/zuul/netty/server/http2/Http2StreamHeaderCleaner.java