Lazy load for non-filtered images

[TomoTsuyuki]

I tested the plugin and found images are not lazy load if the images are not from the plugin (smaller than "Maximum image width").

I don't want to show smaller size of image (like banner), and it's not good quality if it's enlarged, so I set larger size of "Maximum image width".
When we set bigger size of "Maximum image width", most of images are from local storage, but it's not lazy load.
We have hundreds of images in one page, so it's better to lazy load even it's from local storage.