using proxy agent and getting SSL routines:ssl3_get_record:wrong version number:../deps/openssl/openssl/ssl/record/ssl3_record.c:358:

Hi, I am getting this error when using proxies (i have now tried two paid proxies that require auth):

```
SSL routines:ssl3_get_record:wrong version number:../deps/openssl/openssl/ssl/record/ssl3_record.c:358:
```

This is how I am using ytdl-core with `http-proxy-agent`:

```
const agent = new HttpsProxyAgent(proxyURL);
...
const audioStream = ytdl(videoUrl, { quality: lowestQualityFormat.itag, requestOptions: { agent: agent } });
```