XXI Type Pressure Hull Durability Fix

[Nicolas]

I was curious and opened some files with silent editor to see if there is something, and:

In nss_uboat21.zon you have 'colisionableobject'

a type 7c has 350 hitpoints and 21 has 450
7c armor 25 and xxi armor 28

The only weakness i saw was that crash speed, was 2 instead of 0.1 in the 7c meaning that if you are below crush depth you die pretty quickly.

This is on nygm.