Drain will not work on oneself anymore

git-svn-id: http://svn.net-core.org/repos/t-engine4@3446 51575b47-30f0-44d4-a5cc-537603b46e54

game/modules/tome/data/damage_types.lua

@@ -972,7 +972,8 @@ newDamageType{
 	projector = function(src, x, y, type, dam)
 		if _G.type(dam) == "number" then dam = {dam=dam, vim=0.2} end
 		local realdam = DamageType:get(DamageType.BLIGHT).projector(src, x, y, DamageType.BLIGHT, dam.dam)
-		src:incVim(realdam * dam.vim)
+		local target = game.level.map(x, y, Map.ACTOR)
+		if target and target ~= src and realdam > 0 then src:incVim(realdam * dam.vim) end
 	end,
 }