[mod] simple theme: infobox: center the image

searx/static/themes/simple/src/less/style.less

@@ -468,7 +468,7 @@ article.result-images[data-vim-selected] {
       max-width: 100%;
       max-height: 12em;
       display: block;
-      margin: 0;
+      margin: 0 auto;
       padding: 0;
     }