nixos/networkmanager: tiny cleanups

These are the leftovers of an older PR.

a. Send messages to auditd if auditing is enabled.
b. Add missing dbus configuration if dnsmasq is used for DNS

nixos/modules/services/networking/networkmanager.nix

@@ -27,6 +27,7 @@ let
 
     [logging]
     level=${cfg.logLevel}
+    audit=${lib.boolToString config.security.audit.enable}
 
     [connection]
     ipv6.ip6-privacy=2
@@ -508,8 +509,9 @@ in {
 
     security.polkit.extraConfig = polkitConf;
 
-    services.dbus.packages =
-      optional cfg.enableStrongSwan pkgs.strongswanNM ++ cfg.packages;
+    services.dbus.packages = cfg.packages
+      ++ optional cfg.enableStrongSwan pkgs.strongswanNM
+      ++ optional (cfg.dns == "dnsmasq") pkgs.dnsmasq;
 
     services.udev.packages = cfg.packages;
   };