Sometimes, the version field, that is supposed to be a string, was a
null instead. Inspecting other entries, seems like the default for not
having a version should be "", so I made it like that in case the
version was null.
I hope this fixes the issue :^)
Let's move off our custom QuaZip. In the olden times we needed the
custom version of QuaZip, as it was basically unmaintained and on
SourceForge (eww). But nowadays it's maintained and on GitHub. See
new GitHub page: https://github.com/stachenov/quazip
