Fix the command line help message.
Fix the command line help message.

poparteu/openMVG,openMVG/openMVG,openMVG/openMVG,poparteu/openMVG,openMVG/openMVG,openMVG/openMVG,poparteu/openMVG,poparteu/openMVG,openMVG/openMVG