When monsters are fighting among themselves

[hops]

Specifically, when the summons of the Gorbat are fighting himself. ( Gorbat in time-prisoned by warper at the time )

Lua Error: /mod/class/NPC.lua:136: attempt to index local 'src' (a nil value)
At [C]:-1
At /mod/class/NPC.lua:136 die
At /mod/ai//summon.lua:26
At (tail call):-1
At (tail call):-1
At /mod/class/NPC.lua:44 act
At /engine/GameEnergyBased.lua:73 tick
At /engine/GameTurnBased.lua:44 tick
At /mod/class/Game.lua:557

[darkgod]

fixed