Revert "PRELIMINARY: dbus-service: Include system-services directories."

This reverts commit e3484421.

gnu/services/desktop.scm

@@ -65,9 +65,7 @@ (define (services->sxml services)
                             `((includedir
                                ,(string-append dir "/etc/dbus-1/system.d"))
                               (servicedir         ;for '.service' files
-                               ,(string-append dir "/share/dbus-1/services"))
-                              (servicedir         ;for '.service' files
-                               ,(string-append dir "/share/dbus-1/system-services"))))
+                               ,(string-append dir "/share/dbus-1/services"))))
                           services)))
 
         (mkdir #$output)