Gert Cave Final Chest

^^ title, chest does not reference L_DAXE_CHANCE_MULT anymore to track killing of the goblin chieftains set by the map's game master. Change introduced in OCT patch changes.

https://github.com/MSRevive/MSCScripts/commit/360583cd8e898b7e0625ca7695a31726748851c4#diff-345955efa6984626e115ff959201f20fc6d938cecd9744f5edade9489520671f