[fix] simple theme: img tile, shows duplicate information on screen

Remove global title attribute from img tag[1][2] .  In the image result, the
title is already shown from span class title::

    <span class="title">{{ result.title|striptags }}</span>

See commit: 8fbffb1409b

    [fix] simple-theme templates: polish HTML <img> elements

[1] https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img
[2] https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes#attr-title

Reported-by: @dalf https://github.com/searxng/searxng/pull/545#issuecomment-980531215
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/templates/simple/result_templates/images.html

@@ -1,6 +1,6 @@
 <article class="result result-images {% if result['category'] %}category-{{ result['category'] }}{% endif %}">{{- "" -}}
         <a {% if results_on_new_tab %}target="_blank" rel="noopener noreferrer"{% else %}rel="noreferrer"{% endif %} href="{{ result.img_src }}">{{- "" -}}
-                <img class="image_thumbnail" {% if results_on_new_tab %}target="_blank" rel="noopener noreferrer"{% else %}rel="noreferrer"{% endif %} src="{% if result.thumbnail_src %}{{ image_proxify(result.thumbnail_src) }}{% else %}{{ image_proxify(result.img_src) }}{% endif %}" loading="lazy" title="{{ result.title|striptags }}" alt="{{ result.title|striptags }}">{{- "" -}}
+                <img class="image_thumbnail" {% if results_on_new_tab %}target="_blank" rel="noopener noreferrer"{% else %}rel="noreferrer"{% endif %} src="{% if result.thumbnail_src %}{{ image_proxify(result.thumbnail_src) }}{% else %}{{ image_proxify(result.img_src) }}{% endif %}" loading="lazy" alt="{{ result.title|striptags }}">{{- "" -}}
                 <span class="title">{{ result.title|striptags }}</span>{{- "" -}}
         </a>{{- "" -}}
         <div class="detail">{{- "" -}}
@@ -9,9 +9,9 @@
                 <a class="result-detail-next" href="#">{{ icon('chevron-right') }}</a>{{- "" -}}
                 <a class="result-images-source" {% if results_on_new_tab %}target="_blank" rel="noopener noreferrer"{% else %}rel="noreferrer"{% endif %} href="{{ result.img_src }}">
                         {%- if result.thumbnail_src -%}
-                                <img src="" data-src="{{ image_proxify(result.img_src) }}" alt="{{ result.title|striptags }}" title="{{ result.title|striptags }}">
+                                <img src="" data-src="{{ image_proxify(result.img_src) }}" alt="{{ result.title|striptags }}">
                         {%- else -%}
-                                <img src="{{ image_proxify(result.img_src) }}" alt="{{ result.title|striptags }}" loading="lazy" title="{{ result.title|striptags }}">
+                                <img src="{{ image_proxify(result.img_src) }}" alt="{{ result.title|striptags }}" loading="lazy">
                         {%- endif -%}
                 </a>{{- "" -}}
                 <div class="result-images-labels">{{- "" -}}