Bug#792715: opencv: FTBFS with Sphinx 1.3: wrong code to detect Sphinx version

[Simon McVittie]

Control: reopen 792715

On Sat, 15 Aug 2015 at 15:54:33 +0000, Debian Bug Tracking System forwarded:
>    * Fix message when calling sphinx-build without arguments
>      (print_help.diff; closes: #792715).

I'm looking into NMUing opencv for the libstdc++ transition.

This change does not actually address the opencv FTBFS, because opencv
specifically reads sphinx-build's stderr, and the newly patched
sphinx-build writes to stdout.

I personally think the right solution to this is for opencv to stop
checking the sphinx-build version at all, since it doesn't actually
use it for anything, and that's what I intend to NMU if its maintainers
don't object.

Regards,
    S