Weird IP addresses in yahoo_static_hosts.txt

Hey,

after scraping the latest yahoo hosts, I found IPv6 addresses that aren't really valid in the final file:

```
ipv6:::
ipv6:::
ipv6:::
ipv6:::
ipv6:5e6::af
ipv6:5e6::bef
ipv6:5e6::af
ipv6:5e6::bef
ipv6:5e6::af
ipv6:5e6::bef
ipv6:5e6::af
```

Can you please look into this?