[FrameworkBundle] Fixed typo in trace.html.twig

src/Symfony/Bundle/FrameworkBundle/Resources/views/Exception/trace.html.twig

@@ -12,8 +12,8 @@
     in {{ trace.file|format_file(trace.line) }} 
     {% spaceless %}
     <a href="#" onclick="toggle('trace_{{ prefix ~ '_' ~ i }}'); switchIcons('icon_{{ prefix ~ '_' ~ i }}_open', 'icon_{{ prefix ~ '_' ~ i }}_close'); return false;">
-        <img class="toggle" id="icon_{{ prefix ~ '_' ~ i }}_close" alt="-" src="{{ asset('bundles/framework/images/blue_picto_less.gif') }}" style="visibility: {{ 0 == prefix ? 'hidden' : 'display' }}" />
-        <img class="toggle" id="icon_{{ prefix ~ '_' ~ i }}_open" alt="+" src="{{ asset('bundles/framework/images/blue_picto_more.gif') }}" style="visibility: {{ 0 == prefix ? 'display' : 'hidden' }}; margin-left: -18px" />
+        <img class="toggle" id="icon_{{ prefix ~ '_' ~ i }}_close" alt="-" src="{{ asset('bundles/framework/images/blue_picto_less.gif') }}" style="visibility: {{ 0 == i ? 'display' : 'hidden' }}" />
+        <img class="toggle" id="icon_{{ prefix ~ '_' ~ i }}_open" alt="+" src="{{ asset('bundles/framework/images/blue_picto_more.gif') }}" style="visibility: {{ 0 == i ? 'hidden' : 'display' }}; margin-left: -18px" />
     </a>
     {% endspaceless %}
     <div id="trace_{{ prefix ~ '_' ~ i }}" style="display: {{ 0 == i ? 'block' : 'none' }}" class="trace">