Force "Link To" as "None" In Media

You can do this by updating option image_default_link_type

Place this in your theme’s functions.php file.

function change_imgage_default_link() {
        //You may change it media,file,post...
        update_option('image_default_link_type','none');
}
add_action('after_setup_theme', 'change_imgage_default_link');