resolvconf is enabled if generateResolvConf is disabled

[FlorianFreudiger]

#1044 also has the exact opposite effect:
If wsl.wslConf.network.generateResolvConf = false;
then networking.resolvconf.enable is set to true instead of it's default value.

Which in turn breaks my config since I use systemd-resolved, not resolvconf to manage my /etc/resolv.conf.

Originally posted by @FlorianFreudiger in #1044 (comment)

[SuperSandro2000]

This needs a lib.mkIf (config....) false. Can you do a PR with that and validate the fix with your config? Thanks!