Remove rel="noopener" on w3 validator links

weechat/templates/base.html

@@ -84,8 +84,8 @@
       <a href="{% url 'about_weechat.org' %}">{% trans "About WeeChat.org" %}</a>
       &mdash;
       {% trans "Valid" %}:
-      <a href="http://validator.w3.org/check?uri=referer" target="_blank" rel="noopener">HTML5</a> |
-      <a href="http://jigsaw.w3.org/css-validator/check/referer" target="_blank" rel="noopener">CSS</a> |
+      <a href="http://validator.w3.org/check?uri=referer" target="_blank">HTML5</a> |
+      <a href="http://jigsaw.w3.org/css-validator/check/referer" target="_blank">CSS</a> |
       <a href="http://www.w3.org/TR/WCAG20/" target="_blank" rel="noopener">WCAG 2.0<!-- AAA --></a>
     </div>