[WebProfilerBundle] Added security icon for the Web Profiler menu

src/Symfony/Bundle/SecurityBundle/Resources/views/Collector/security.html.twig

@@ -16,7 +16,8 @@
 {% endblock %}
 
 {% block menu %}
-<span class="picto">
+<span class="label">
+    <span class="icon"><img src="{{ asset('bundles/webprofiler/images/profiler/security.png') }}" alt="" /></span>
     <strong>Security</strong>
 </span>
 {% endblock %}