ToME: the Tales of Maj'Eyal

Every time a monster died on tannens tower level 4, i got a error report similar to the following.

[LOG] #{bold}#Cheradenine killed greater multi-hued wyrm!#{normal}#
stack traceback:
/data/maps/zones/tannen-tower-4.lua:62: in function </data/maps/zones/tannen-tower-4.lua:55>
(tail call): ?
/engine/interface/ActorLife.lua:81: in function 'die'
/mod/class/Actor.lua in function </mod/class/Actor.lua:1069>
(tail call): ?
/engine/interface/ActorLife.lua:70: in function 'takeHit'
/data/damage_types.lua:114: in function 'projector'
/mod/class/interface/Combat.lua:253: in function 'attackTargetWith'
/data/talents/divine/guardian.lua:85: in function 'action'
/engine/interface/ActorTalents.lua:117: in function </engine/interface/ActorTalents.lua:111>
Lua Error: /engine/interface/GameTargeting.lua:124: /data/maps/zones/tannen-tower-4.lua:62: attempt to index upvalue 'a' (a nil value)
At [C]:-1
At [C]:-1 error
At /engine/interface/GameTargeting.lua:124 fct
At /engine/interface/GameTargeting.lua:130 targetMode
At /engine/interface/GameTargeting.lua:181 ?
At /engine/KeyBind.lua:198

fixed