Update opensfm/commands/export_openmvs.py
Update opensfm/commands/export_openmvs.py

Co-Authored-By: mribbons <99a50b83c134b17be1e4b8bf5c55e628b3981c0e@gmail.com>
oscarlorentzon/OpenSfM,oscarlorentzon/OpenSfM,oscarlorentzon/OpenSfM,oscarlorentzon/OpenSfM,mapillary/OpenSfM,oscarlorentzon/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM