I didn't think you'd be so picky.
The code uses the minetest.safe_file_write function.
According to changelog I looked at it added in minetest version 0.4.17
I could use another function instead. But I don't see the point in maintaining legacy code.
I make the module look forward.
and: There is no option to select only 0.4.17 in the checkbox (without 0.4.16)