nixos/mate: enable services.gnome.glib-networking

This is already done in the 5 other desktop environments I maintain, I decided that I don't mind adding another one.

Changed files
+1
nixos
modules
services
x11
desktop-managers
+1
nixos/modules/services/x11/desktop-managers/mate.nix
···
programs.system-config-printer.enable = (mkIf config.services.printing.enable (mkDefault true));
services.gnome.at-spi2-core.enable = true;
+
services.gnome.glib-networking.enable = true;
services.gnome.gnome-keyring.enable = true;
services.udev.packages = [ pkgs.mate.mate-settings-daemon ];
services.gvfs.enable = true;