use peers from magnet link

rqbit 8.0.0 throws

> error adding magnet:?xt=urn:btih:xxx&x.pe=127.0.0.1:12345
> error adding torrent
> no known way to resolve peers (no DHT, no trackers, no initial_peers)

i am starting the server with

```
rqbit --disable-dht --disable-upnp-port-forward server start ./rqbit-downloads
```

magnet URIs allow adding peers like `x.pe=127.0.0.1:12345`
