geogebra: add archive.org link for 5-0-444-0

The `geogebra` package is subject to break as upstream removes versioned
packages from their download server when five new releases are comming.

This is why I had to fix almost monthly the package by bumping the
version (these can be found by running `git log --online | grep
geogebra:`). As the package didn't cause any issues for several months
now I guess that using `archive.org` seems to be a suitable solution for
now.

/cc @sternenseemann @matthewbauer