`nodes.hashvault.pro` cannot be resolved
P2Pool errors with:
```
P2Pool resolve_host failed for nodes.hashvault.pro
```
when trying to connect to `nodes.hashvault.pro` with:
```
./p2pool --wallet <WALLET> --host nodes.hashvault.pro --rpc-port 18081 --zmq-port 18083
```

Connecting to the raw IP works fine though:
```
ping nodes.hashvault.pro
PING nodes.hashvault.pro (185.240.242.36) 56(84) bytes of data.

./p2pool --wallet <WALLET> --host 185.240.242.36 --rpc-port 18081 --zmq-port 18083
```

The `.pro` TLD is included in this list by ICANN: https://data.iana.org/TLD/tlds-alpha-by-domain.txt so this might be a bug in P2Pool's domain parsing?