bug report! If koa and http2server are used together, the response with method "head" request will never end!
bug report! If koa and http2server are used together, the response with method "head" request will never end!
```js
import http2 from "http2";
import Koa from "koa";
import fs from "fs";
import { fileURLToPath } from "url";
import { join, dirname } from "path";
const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);
const app = new Koa();
const selfSignedKey = join(__dirname, "./certs/self-signed.key.pem");
const selfSignedCert = join(__dirname, "./certs/self-signed.cert.pem");
app.use((ctx) => {
    ctx.body = "Hello Koa";
});
const config = {
    sslKey: fs.readFileSync(selfSignedKey).toString(),
    sslCert: fs.readFileSync(selfSignedCert).toString(),
};
const serverHandler = app.callback();
const httpsopt = { cert: config.sslCert, key: config.sslKey };
const server = http2.createSecureServer(httpsopt, serverHandler);

server.on("listening", () => {
    console.log(`Server listening on ` + JSON.stringify(server.address()));
});
server.listen(3000);
```

```json
{
    "type": "module",
    "dependencies": {
        "koa": "^2.13.1"
    }
}
```
```shell
node index.js
```
Initiate a "head" request in the browser.
```
Request URL: https://localhost:3000/
Referrer Policy: strict-origin-when-cross-origin
```
```
:authority: localhost:3000
:method: HEAD
:path: /
:scheme: https
accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
accept-encoding: gzip, deflate, br
accept-language: zh-CN,zh;q=0.9
referer: https://localhost:3000/
sec-ch-ua: " Not;A Brand";v="99", "Google Chrome";v="91", "Chromium";v="91"
sec-ch-ua-mobile: ?0
sec-fetch-dest: empty
sec-fetch-mode: cors
sec-fetch-site: same-origin
upgrade-insecure-requests: 1
user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.106 Safari/537.36
```
the response with method "head" request will never end!