fix error management in preprocessing (#414)
fix error management in preprocessing (#414)


OpenNMT/OpenNMT,jsenellart/OpenNMT,OpenNMT/OpenNMT,jungikim/OpenNMT,jsenellart-systran/OpenNMT,jsenellart/OpenNMT,jsenellart-systran/OpenNMT,jsenellart/OpenNMT,jungikim/OpenNMT,OpenNMT/OpenNMT,jungikim/OpenNMT,jsenellart-systran/OpenNMT