Update smart_open/gcs.py
Update smart_open/gcs.py

Co-Authored-By: Radim Řehůřek <b1c1d8736f20db3fb6c1c66bb1455ed43909f0d8@radimrehurek.com>
RaRe-Technologies/smart_open,piskvorky/smart_open,RaRe-Technologies/smart_open