Fix examples

If there is no namespace declared in the example, the backslash before the class name is not necessary and can be confusing

_posts/05-05-01-PHP-and-UTF8.md

@@ -84,13 +84,13 @@ $string = mb_substr($string, 0, 15);
 // Connect to a database to store the transformed string
 // See the PDO example in this document for more information
 // Note the `set names utf8mb4` commmand!
-$link = new \PDO(   
+$link = new PDO(
     'mysql:host=your-hostname;dbname=your-db;charset=utf8mb4',
     'your-username',
     'your-password',
     array(
-        \PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION,
-        \PDO::ATTR_PERSISTENT => false
+        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
+        PDO::ATTR_PERSISTENT => false
     )
 );