Thanks LouisGac !
Effectively, my server is shared hosting.

It works like a charm ! I can update LS

As there were quite a few people with the same problem it became clear that this is not just a configuration problem of one specific user.

Thank you, Louis, for skipping in and solving that (or at least providing a quick work around).

I added an "ignore button" for the not enough space case. It's available in the last master version on github.
We're going to provide an update of the updater to correct it. So, people on shared hosting will not have to manually correct this bug before updating. It's also a good occasion to test live the updater of the ComfortUpdate.

Coming soon :

Thank you LouisGac!

Actually, I did the update manually because I thought I needed it urgently to solve my other issues.