buildbucket: fixed typo
buildbucket: fixed typo

follow_redirects instead of follow_redirect in urlfetch call.

TBR=vadimsh@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1028533005

nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra