Fix condition for new typo of setting (#89)

* Fix condition for new typo of setting
* Add moreblocks in depends

depends.txt

@@ -5,3 +5,4 @@ stairs
 xpanes
 fire?
 oresplus?
+moreblocks?

handlers/registration.lua

@@ -122,8 +122,10 @@ function xdecor.register(name, def)
 
 	minetest.register_node("xdecor:"..name, def)
 
-	if minetest.settings:get_bool("disable_xdecor_workbench") and 
-	  (minetest.get_modpath("moreblocks") or minetest.get_modpath("stairs")) then
+	local workbench = minetest.settings:get_bool("enable_xdecor_workbench")
+
+	if workbench == false and
+	   (minetest.get_modpath("moreblocks") or minetest.get_modpath("stairs")) then
 		if xdecor.stairs_valid_def(def) then
 			xdecor_stairs_alternative("xdecor:"..name, def)
 		end