My debian.list has been changed, now points to
deb
========= SCRAPER REMOVED AN EMBEDDED LINK HERE ===========
url was:"http://ftp.gr.debian.org/debian/"
linktext was:"http://ftp.gr.debian.org/debian/"
====================================
wheezy main contrib non-free

I can't reproduce the error and I'm not sure if is a bug.
I think that the file was been changed after dist-upgrade, but I'm not sure.
I have done also other operations like reinstall antix-cc-full-antix, but I don't remember any warning related to debian.list

Yes it gets changed when desktop-defaults-full gets upgraded. There should also be saved copies in /etc/apt/sources.d.saved