Merge pull request #237003 from pacien/ddclient-remove-ipv6-opt

nixos/ddclient: remove obsolete ipv6 option

nixos/modules/services/networking/ddclient.nix

···
     ${lib.optionalString (cfg.zone != "")   "zone=${cfg.zone}"}
     ssl=${boolToStr cfg.ssl}
     wildcard=YES
-    ipv6=${boolToStr cfg.ipv6}
     quiet=${boolToStr cfg.quiet}
     verbose=${boolToStr cfg.verbose}
     ${cfg.extraConfig}
···
         in if value != "" then [ value ] else []))
     (mkRemovedOptionModule [ "services" "ddclient" "homeDir" ] "")
     (mkRemovedOptionModule [ "services" "ddclient" "password" ] "Use services.ddclient.passwordFile instead.")
+    (mkRemovedOptionModule [ "services" "ddclient" "ipv6" ] "")
   ];
 
   ###### interface
···
           Whether to use SSL/TLS to connect to dynamic DNS provider.
         '';
       };
-
-      ipv6 = mkOption {
-        default = false;
-        type = bool;
-        description = lib.mdDoc ''
-          Whether to use IPv6.
-        '';
-      };
-
 
       quiet = mkOption {
         default = false;