Shady Cornac man going away wont fail the achievement for saving derth inhabitants

git-svn-id: http://svn.net-core.org/repos/t-engine4@5012 51575b47-30f0-44d4-a5cc-537603b46e54

game/modules/tome/data/zones/town-derth/npcs.lua

@@ -112,4 +112,5 @@ newEntity{ base = "BASE_NPC_DERTH_TOWN",
 		self.seen_by = nil
 		self:doEmote("Hey you. Come here.", 60)
 	end,
+	on_die = false,
 }