feat: deactivate opencv threads also when num_proc is 1
feat: deactivate opencv threads also when num_proc is 1

oscarlorentzon/OpenSfM,oscarlorentzon/OpenSfM,oscarlorentzon/OpenSfM,oscarlorentzon/OpenSfM,oscarlorentzon/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM