Automatic byteline setting doesn't work in init file

[merces]

I added a set byteline auto command with c5e074c. It works, but calculating the most optimum number of bytes per line requires screen.width to be populated, which happens after .dz6init file is read. To reproduce:

1. Add a set byteline auto line to ~/.dz6init.
2. Open dz6.

Expected behaviour: automatic byteline setting works.

What actually happens: byteline is set to the default value (16).