Small improvements on DNS setting page with DNSSEC
We should probably not allow users to enable/disable DNSSEC for every single setting.
In case of unused forwarding there is not reason to not use DNSSEC.
In case of pre-defined forwarders (such as CZ.NIC or Cloudflare) it is know if they support DNSSEC or not (and they do) so user should not be able to disable/enable DNSSEC to not insecure/break DNS.
There are only two cases where it makes sense to disable DNSSEC and that is:
- Provider's resolver
- Custom resolver