Gallery with one preview image but no pagination

I used to have just one preview image for my galleries without pagination. This was possible through inserting the following code at the end of the nggallery.css file

/* For NextGen Gallery. Displays thumbnails on a page, and when you click each thumbnail opens it's own gallery. Normally when you insert a gallery, it displays all the thumbnails in the gallery. This hack will hide all the thumbnails except the first one. Make sure you don't display [show slideshow], because that will be the first child.
Simply add this to the nggallery.css file. */

div.ngg-gallery-thumbnail-box { display:none; }
div.ngg-galleryoverview div:first-child { display:block; }

Since the update to WP 4.0 and NextCellent 1.9.23 this isn’t working anymore.

I tried to use the [nggallery id=294 images=1] shortcode, but I don’t know how to get rid of the pagination.

Do you have any idea to solve this?

https://wordpress.org/plugins/nextcellent-gallery-nextgen-legacy/