fix on_build event entities

control.lua

@@ -73,7 +73,7 @@ local function render_text(drill, time_to_live)
 end
 
 py.on_event(py.events.on_built(), function(event)
-	local drill = event.created_entity or event.entity
+	local drill = event.entity
 	local drill_base = derrick_types[drill.name]
 	if not drill_base then return end