The minetest icon is in fact licensed under CC-BY-SA 3.0 [1].
This means that the modified logo must be licensed under that license
as well.
This means that the antifeature can be removed.
See also the upstream commit [2].
[1]: https://forum.minetest.net/viewtopic.php?p=63922#p63922
[2]: 45987b9748