Fix ddclient extraConfig variable

[LasseBlaauwbroek]

Motivation for this change

The ddclient has a catch-all extraConfig variable that is added below the domain variable in the config script. However, the domain should always be last in the config. So I've moved it below extraConfig.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

---

[tomberek]

The documentation suggest multiple hosts can be separated in this manner:

For example:                                                                                                        
  protocol=hammernode1, \                                                                                           
  login=my-hn-login, password=my-hn-password  myhost.hn.org                                                         
  login=my-login, password=my-password  myhost.dyndns.org,my2nd.dyndns.org      
specifies two host definitions.

I use the configFile approach when the config gets too complicated. I have no issues with this PR.

[matthiasbeyer]

@LasseBlaauwbroek please rebase this PR to resolve conflicts.

[LasseBlaauwbroek]

Done

[matthiasbeyer]

Master looks different already: https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/services/networking/ddclient.nix#L23

[LasseBlaauwbroek]

Yes, but the lines

    ${lib.concatStringsSep "," cfg.domains}
    ${cfg.extraConfig}

still need to be exchanged. Because the domains are still expected to go below anything else.

[matthiasbeyer]

See #63087

[matthewbauer]

Thanks for the contribution! Sorry for not noticing this earlier.