The exit code for 'python -msphinx' is incorrect

[kvalev]

Subject: Sphinx did not exit with the correct exit code

Feature or Bugfix

• Bugfix

Purpose

The exit code of the sphinx main method was ignored, so the process always exited with an exit code of 0, even if there were warnings and the -W flag was set.

Relates

• Sphinx should exit with non zero exit code on error #508

[tk0miya]

Thanks!