IPv6 ufw check skip if ufw is disabled

[OleksanderSalamatov]

Currently we have a precondition check, that look at ufw config to verify if IPv6 is disabled there. On vultr, where the ufw(with IPv6) is enabled by default, it is not enough to just disable ufw, we also need to disable IPv6 manually in config, then reload ufw, then disable it for everything to work correctly.

It will be good to have check that ufw is enabled or disabled, before we check that IPv6 there is enabled or disabled