use the right mesecon:receptor_* call for on/off blinkyplant

mesecons_blinkyplant/init.lua

@@ -87,11 +87,12 @@ minetest.register_abm({
 	action = function(pos, node, active_object_count, active_object_count_wider)
 		if node.name == "mesecons_blinkyplant:blinky_plant_off" then
 			minetest.add_node(pos, {name="mesecons_blinkyplant:blinky_plant_on"})
+			mesecon:receptor_on(pos)
 		else
 			minetest.add_node(pos, {name="mesecons_blinkyplant:blinky_plant_off"})
+			mesecon:receptor_off(pos)
 		end
 		nodeupdate(pos)	
-		mesecon:receptor_on(pos)
 	end,
 })