Remove useless, empty callbacks

mods/default/functions.lua

@@ -102,31 +102,6 @@ function default.register_falling_node(nodename, texture)
 	end
 end
 
---
--- Global callbacks
---
-
--- Global environment step function
-function on_step(dtime)
-	-- print("on_step")
-end
-minetest.register_globalstep(on_step)
-
-function on_placenode(p, node)
-	--print("on_placenode")
-end
-minetest.register_on_placenode(on_placenode)
-
-function on_dignode(p, node)
-	--print("on_dignode")
-end
-minetest.register_on_dignode(on_dignode)
-
-function on_punchnode(p, node)
-end
-minetest.register_on_punchnode(on_punchnode)
-
-
 --
 -- Lavacooling
 --