device: make sure we emit PropertiesChanged signal once we set sysfs

src/core/device.c

@@ -83,6 +83,8 @@ static int device_set_sysfs(Device *d, const char *sysfs) {
         }
 
         d->sysfs = TAKE_PTR(copy);
+        unit_add_to_dbus_queue(UNIT(d));
+
         return 0;
 }