Hello!as a workaround you can set empty `update_information_url` in `~/.minetest/minetest.conf`.
For Debian developer maintaining minetest, this can be patched in `src/defaultsettings.cpp` same way by setting it to empty string.
Please, consider this message also as a request to bump minetest up to 5.8.0 version.
Thank you! -- David Heidelberg