[3.8] bpo-34293: Fix PDF documentation paper size (GH-8585) (GH-15816)

The "A4" pdfs were previously the wrong size due to a change in the options in Sphinx 1.5.

See also sphinx-doc/sphinxGH-5235
(cherry picked from commit b5381f669718aa19690f42f3b8bd88f03045b9d2)

Authored-by: Jean-François B <jfbu@free.fr>
2 files changed