This fixes Zombified Ian

When Ian(or other Corgi's) are dead, and you put something on their head, instead of the normal message which appears as when they were alive, this is now shown : 

usr << "<span class ='notice'>There is merely a dull, lifeless look in [real_name]'s eyes as you put the [item_to_add] on \him.</span>"

Thus no more zombie Ian when dressing his corpse up!

Fixes #3650
Doesn't this check need to be present in a place where both Usr and health<=0 will call it?
Otherwise you could put items you can't drop on Ian when he's dead.