nixos: correct improper uses of mkEnableOption, clarify service descriptions

Several service definitions used `mkEnableOption` with text starting
with "Whether to", which produced funny option descriptions like
"Whether to enable Whether to run the rspamd daemon..".

This commit corrects this, and adds short descriptions of services
to affected service definitions.

3 files changed, 3 insertions, 3 deletions

diff --git a/nixos/modules/services/networking/pptpd.nix b/nixos/modules/services/networking/pptpd.nix
index 56a612b91052..d8b9e8f8341a 100644
--- a/nixos/modules/services/networking/pptpd.nix
+++ b/nixos/modules/services/networking/pptpd.nix
@@ -5,7 +5,7 @@ with lib;
 {
   options = {
     services.pptpd = {
-      enable = mkEnableOption "Whether pptpd should be run on startup.";
+      enable = mkEnableOption "pptpd, the Point-to-Point Tunneling Protocol daemon";
 
       serverIp = mkOption {
         type        = types.string;
diff --git a/nixos/modules/services/networking/xl2tpd.nix b/nixos/modules/services/networking/xl2tpd.nix
index 46111a76af80..d0a3ed7bb5e0 100644
--- a/nixos/modules/services/networking/xl2tpd.nix
+++ b/nixos/modules/services/networking/xl2tpd.nix
@@ -5,7 +5,7 @@ with lib;
 {
   options = {
     services.xl2tpd = {
-      enable = mkEnableOption "Whether xl2tpd should be run on startup.";
+      enable = mkEnableOption "xl2tpd, the Layer 2 Tunnelling Protocol Daemon";
 
       serverIp = mkOption {
         type        = types.string;
diff --git a/nixos/modules/services/networking/xrdp.nix b/nixos/modules/services/networking/xrdp.nix
index 61f22a366a02..9ed3025e47d4 100644
--- a/nixos/modules/services/networking/xrdp.nix
+++ b/nixos/modules/services/networking/xrdp.nix
@@ -36,7 +36,7 @@ in
 
     services.xrdp = {
 
-      enable = mkEnableOption "Whether xrdp should be run on startup.";
+      enable = mkEnableOption "xrdp, the Remote Desktop Protocol server";
 
       package = mkOption {
         type = types.package;