Lua error whith shadows in the shadow crypt

[ghostbuster]

Actors in the shadow crypt do not have a lite defined. This creates a lua error with the shadow ai.
This can be fixed by either:
- adding them a 0 radius lite
- changing line 39 of mod/ai/shadows.lua
from
(act.lite > 0)
to something like
(act.lite and (act.lite > 0))