[enh] add image proxy to image results

searx/templates/courgette/result_templates/images.html

 <div class="image_result">
     <p>
-        <a href="{{ result.img_src }}"><img src="{{ result.img_src }}" title="{{ result.title|striptags }}" alt="{{ result.title|striptags }}"/></a>
+        <a href="{{ result.img_src }}"><img src="{{ image_proxify(result.img_src) }}" title="{{ result.title|striptags }}" alt="{{ result.title|striptags }}"/></a>
         <span class="url"><a href="{{ result.url }}" class="small_font">{{ _('original context') }}</a></span>
     </p>
-</div>
+</div>

searx/templates/default/result_templates/images.html

 <div class="image_result">
     <p>
-        <a href="{{ result.img_src }}"><img src="{{ result.img_src }}" title="{{ result.title|striptags }}" alt="{{ result.title|striptags }}" /></a>
+        <a href="{{ result.img_src }}"><img src="{{ image_proxify(result.img_src) }}" title="{{ result.title|striptags }}" alt="{{ result.title|striptags }}" /></a>
         <span class="url"><a href="{{ result.url }}" class="small_font">{{ _('original context') }}</a></span>
     </p>
 </div>

searx/templates/oscar/result_templates/images.html

 {% from 'oscar/macros.html' import draw_favicon %}
 
 <a href="{{ result.img_src }}" data-toggle="modal" data-target="#modal-{{ index }}">
-    <img src="{{ result.img_src }}" alt="{{ result.title|striptags }}" title="{{ result.title|striptags }}" class="img-thumbnail">
+    <img src="{{ image_proxify(result.img_src) }}" 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">