fix noffix missing last subtoken problem for BPE.lua
fix noffix missing last subtoken problem for BPE.lua

jungikim/OpenNMT,monsieurzhang/OpenNMT,jsenellart/OpenNMT,OpenNMT/OpenNMT,jsenellart/OpenNMT,jungikim/OpenNMT,jsenellart-systran/OpenNMT,OpenNMT/OpenNMT,monsieurzhang/OpenNMT,jsenellart-systran/OpenNMT,da03/OpenNMT,da03/OpenNMT,jsenellart-systran/OpenNMT,da03/OpenNMT,jungikim/OpenNMT,jsenellart/OpenNMT,monsieurzhang/OpenNMT,OpenNMT/OpenNMT