[BUGFIX] Cannot render HTML with Sphinx 1.1.3

The default templating engine for Sphinx is Jinja and Jinja requires
Python at least Python 2.6.

Change-Id: I6a58070eb63a41b39f08e2733d69d44b17888ab2
Fixes: #53248
Reviewed-on: https://review.typo3.org/25092
Reviewed-by: Xavier Perseguers
Tested-by: Xavier Perseguers