I've updated the package now. I used original NAS542 tar/gzip. Three files are changed:
control.tar.gz: MidnightCommander.control
control.tar.gz: MidnightCommander.postinst
data.tar.gz: /etc/init.d/MidnightCommander
It is working as long the internal repository isn't used. While testing the file /tmp/.MetaRepository/tmp/lasturl was created and set to the internal repository where wget can't be used. Nevertheless I used my test repository on zyxel.ddnss.eu afterwards lasturl was still there and pointed to the internal repository. After I deleted the lasturl file the new MC package is able to download the libiconf.so.2.tar.gz file.