Fix the brotherhood quest

git-svn-id: http://svn.net-core.org/repos/t-engine4@3122 51575b47-30f0-44d4-a5cc-537603b46e54

game/modules/tome/data/quests/brotherhood-of-alchemists.lua

@@ -108,6 +108,7 @@ end
 --called in the on_die functions of ingredient-dropping monsters to determine if they should really drop their ingredient
 need_part = function(self, player, ingredient, monster)
 	if self:isEnded() then return end
+	if not player or game.party:hasMember(player) then return end
 	local list = self.needed_ingredients
 	local needed = false
 	local ing_list = mod.class.Object:loadList("/data/general/objects/elixir-ingredients.lua")