[fix] images modal with infinite scroll

searx/templates/oscar/result_templates/images.html

 {% from 'oscar/macros.html' import draw_favicon %}
 
-<a href="{{ result.img_src }}" {% if results_on_new_tab %}target="_blank" rel="noopener noreferrer"{% else %}rel="noreferrer"{% endif %} data-toggle="modal" data-target="#modal-{{ index }}">
+<a href="{{ result.img_src }}" {% if results_on_new_tab %}target="_blank" rel="noopener noreferrer"{% else %}rel="noreferrer"{% endif %} data-toggle="modal" data-target="#modal-{{ index }}-{{pageno}}">
     <img src="{% if result.thumbnail_src %}{{ image_proxify(result.thumbnail_src) }}{% else %}{{ image_proxify(result.img_src) }}{% endif %}" alt="{{ result.title|striptags }}" title="{{ result.title|striptags }}" class="img-thumbnail">
 </a>
 
-<div class="modal fade" id="modal-{{ index }}" tabindex="-1" role="dialog" aria-hidden="true">
+<div class="modal fade" id="modal-{{ index }}-{{ pageno }}" tabindex="-1" role="dialog" aria-hidden="true">
     <div class="modal-dialog">
         <div class="modal-wrapper">
             <div class="modal-header">