gcs: Fix compile after removal of SetOpaque
gcs: Fix compile after removal of SetOpaque

It turns out that the SetOpaque call isn't needed any more as Google
aren't returning paths with `%2F` in any more so remove the whole
complication.

Fixes #676
Fixes #660

arcimboldo/rclone,B4dM4n/rclone,seuffert/rclone,jackschmidt/rclone,B4dM4n/rclone,seuffert/rclone,yonjah/rclone,olihey/rclone,jackschmidt/rclone,arcimboldo/rclone,kynikos/rclone,jackschmidt/rclone,ncw/rclone,kynikos/rclone,kynikos/rclone,yonjah/rclone,arcimboldo/rclone,jackschmidt/rclone,ncw/rclone,ncw/rclone,B4dM4n/rclone,olihey/rclone,B4dM4n/rclone,kynikos/rclone,seuffert/rclone,yonjah/rclone,yonjah/rclone,olihey/rclone,seuffert/rclone,ncw/rclone,olihey/rclone,arcimboldo/rclone