gcs-oauth2-boto-plugin: upgraded package to upstream

Upgraded dev-python/gcs-oauth2-boto-plugin to version 2.5 for newer gsutil.

BUG=chromium:1019337
TEST=CQ passes

Change-Id: Ifa759999f916b4be24b495431d5c03620fe1b9f5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/2033616
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Chris McDonald <cjmcdonald@chromium.org>
3 files changed