GitLab

Summary:
With the introduction of tutorials, the turn around time for doc build
has become longer. By default, the tutorial is not built but SPHINXOPT=-W
treats it as error.

This commit disable the option for the local build while keeping it
for the CI.

Pull Request resolved: https://github.com/pytorch/audio/pull/2013

Reviewed By: carolineechen

Differential Revision: D32538952

Pulled By: mthrok

fbshipit-source-id: eae4ffd87100dff466f91abfe26a82aa702d605a