Fixes human/checkarmor getting the armour...

...value for the wrong body part.

Whoever put ran_zone() in there wasn't thinking straight, as it's not
going to affect the part that actually gets damaged.

(cherry picked from commit 5a3c7dc432121e8e76e8c47b221b4c8f5667530b)
Armour can turn sharp attacks into blunt ones

Kind of messy, but I couldn't find another way to do it without
reworking a lot of the mob defence procs.

(cherry picked from commit 37b71c81fbb91091bfde994b4860f298535fda16)