Fix anti-antimagic quest invuln sometimes bugging

I guess something can have a faction but no setEffect.

game/modules/tome/data/quests/anti-antimagic.lua

@@ -120,7 +120,7 @@ myssil_dies = function(self)
 
 	local corr = nil
 	for uid, e in pairs(game.level.entities) do
-		if e.faction == "rhalore" then e:setEffect(e.EFF_VICTORY_RUSH_ZIGUR, 20, {}) end
+		if e.faction == "rhalore" and e.setEffect then e:setEffect(e.EFF_VICTORY_RUSH_ZIGUR, 20, {}) end
 		if e.define_as and e.define_as == "GRAND_CORRUPTOR" then corr = e end
 	end
 	if not corr then return end