Fixed another missing include

Author: javiereguiluz

reference/forms/types/timezone.rst

@@ -145,6 +145,8 @@ These options inherit from the :doc:`ChoiceType </reference/forms/types/choice>`
 
 These options inherit from the :doc:`FormType </reference/forms/types/form>`:
 
+.. include:: /reference/forms/types/options/attr.rst.inc
+
 .. include:: /reference/forms/types/options/data.rst.inc
 
 .. include:: /reference/forms/types/options/disabled.rst.inc