minor #8088 Use Twig's namespaced paths (yceruto)

This PR was merged into the 2.7 branch.

Discussion
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Use Twig's namespaced paths

This only solves an inconsistency in this article. Both paths are valid and functional by default in Symfony. But http://symfony.com/doc/2.7/templating/namespaced_paths.html:

> As an added bonus, the namespaced syntax is faster.

What do you think about using it everywhere?

Commits
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bac2313 Use Twig's namespaced paths

Author: weaverryan

profiler/data_collector.rst

@@ -153,7 +153,7 @@ block and set the value of two variables called ``icon`` and ``text``:
 
 .. code-block:: html+twig
 
-    {% extends 'WebProfilerBundle:Profiler:layout.html.twig' %}
+    {% extends '@WebProfiler/Profiler/layout.html.twig' %}
 
     {% block toolbar %}
         {% set icon %}