[WebProfilerBundle] Always use the default background color for counters

src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/exception.html.twig

@@ -11,7 +11,7 @@
     <strong>Exception</strong>
     <span class="count">
         {% if collector.hasexception %}
-            <span class="error">1</span>
+            <span>1</span>
         {% endif %}
     </span>
 </span>