Adjust generated config to prevent IPv6 leak

[peterhirn]

Check: https://ipv6leak.com/
Fix: https://www.reddit.com/r/WireGuard/comments/nl2uxl/comment/gzgaxo8

- AllowedIPs = 0.0.0.0/0
+ AllowedIPs = 0.0.0.0/0, ::/0 

[Avnsx]

This makes definetly sense.

Would also recommend checking with https://dnsleaktest.com/ if your configurations worked.

However personally I would rather just entirely disable IPv6 in your router.
I think it would have a lot of compatibility issues, to route IPv6 traffic through the wireguard tunnel to a IPv4 VPN destination server for example.