networking.vpnc: remove option

This PR is part of the networking.* namespace cleanup.

The Cisco VPN module is currently of limited value since it just creates
config files but does not manage services. The same functionality can be
achieved by using _environment.etc_ instead.

It would be a different situation if we had a full service module. So if
you are annoyed by this change, please consider write a more featureful
module and put its options unter _services.networking.vpnc_.

Note that this change removes options for *Cisco VPN*, not
*networkmanager-vpn*.

nixos/modules/config/vpnc.nix

@@ -1,41 +0,0 @@
-{ config, lib, ... }:
-
-with lib;
-
-let
-  cfg = config.networking.vpnc;
-  mkServiceDef = name: value:
-    {
-      name = "vpnc/${name}.conf";
-      value = { text = value; };
-    };
-
-in
-{
-  options = {
-    networking.vpnc = {
-      services = mkOption {
-       type = types.attrsOf types.str;
-       default = {};
-       example = literalExample ''
-         { test = '''
-             IPSec gateway 192.168.1.1
-             IPSec ID someID
-             IPSec secret secretKey
-             Xauth username name
-             Xauth password pass
-           ''';
-         }
-       '';
-       description = 
-         ''
-           The names of cisco VPNs and their associated definitions
-         '';
-      };
-    };
-  };
-
-  config.environment.etc = mapAttrs' mkServiceDef cfg.services;
-}
-
-