Merge branch '3.4' into 4.3

* 3.4:
  Fix ctype links

Author: javiereguiluz

reference/constraints/Type.rst

@@ -171,5 +171,5 @@ Also, you can use ``ctype_()`` functions from corresponding
 Make sure that the proper :phpfunction:`locale <setlocale>` is set before
 using one of these.
 
-.. _built-in PHP extension: https://php.net/book.ctype.php
-.. _a list of ctype functions: https://php.net/ref.ctype.php
+.. _built-in PHP extension: https://php.net/book.ctype
+.. _a list of ctype functions: https://php.net/ref.ctype