[NTG-context] Missing parinitskips in \normalizelinemode=0

[Max Chernoff]

Hi Hans,

> i'll bypass that warnign when the mode is zero

I saw that you made that change in the latest upload, thanks.
Unfortunately, I'm still getting the same output:

   luatex warning  > linebreak: list seems already prepared
   luatex warning  > linebreak: [ leftinit | rightinit | leftfill | rigthfill ] expected
   nil
   
Also, what's causing me issues isn't the warning but rather that
tex.linebreak is returning nil instead of an info table as the second
return value.

> btw, you need to work with a copy of the list

Now that you point that out, I'm actually surprised that that example
worked at all. The real code does use a copy of the list though (and
also uses the proper callback interfaces instead of "system.callbacks.
permitoverloads")

Thanks,
-- Max