[#5948] Removed caution about 5.3.6 as 5.3.9 is required

Author: wouterj

components/dom_crawler.rst

@@ -300,12 +300,6 @@ and :phpclass:`DOMNode` objects:
 
     The ``html`` method is new in Symfony 2.3.
 
-    .. caution::
-
-        Due to an issue in PHP, the ``html()`` method returns wrongly decoded HTML
-        entities in PHP versions lower than 5.3.6 (for example, it returns ``•``
-        instead of ``•``).
-
 Links
 ~~~~~