Fixed a minor lua bug

data/monstergen.lua

@@ -136,7 +136,7 @@ local demon = {
 }
 
 local function concat(table1, table2)
-	for i=0,#table2 do
+	for i=1,#table2 do
 		table1[#table1+1] = table2[i]
 	end
 	return table1