Fix typo

The method ignoreUnreadableDirs() had an extra "`" char

Author: lucascourot

components/finder.rst

@@ -97,7 +97,7 @@ Exclude directories from matching with the
     $finder->in(__DIR__)->exclude('ruby');
 
 .. versionadded:: 2.3
-   The :method:`Symfony\\Component\\Finder\\Finder::ignoreUnreadableDirs``
+   The :method:`Symfony\\Component\\Finder\\Finder::ignoreUnreadableDirs`
    method was added in Symfony 2.3.
 
 It's also possible to ignore directories that you don't have permission to read::