I haven't touched the code in a while, so this may or may not work, but the problem is with the module_scripts still having the French Light Infantry in its code. If you want to remove the French Light infantry, you will also have to remove them in the module_scripts, which would in effect require you to modify other scripts containing the unit.
I would suggest one of the two for an easier approach:
1) Just replace it with another unit: I'm sure you can think of some other unit to replace it with.
2) Instead of deleting the line of code,
cut it, and paste it after the line of code below:
["multiplayer_end","{!}multiplayer_end","{!}multiplayer_end", 0, 0, 0, fac_austria, [], 0, 0, 0, 0, 0],
Again, I must stress that I haven't touched the NW Module System in a while, so this may be incorrect. No harm in trying, though.