cipd: handle err
cipd: handle err

This is for
https://screenshot.googleplex.com/4f5Rcsn7yrPura7

Bug: 1143123
Change-Id: I56e85694f28f61abfe6fbf04212dc9a67814940c
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/3013153
Auto-Submit: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
Commit-Queue: Andrii Shyshkalov <a30c74fa30536fe7ea81ed6dec202e35e149e1fd@google.com>
Reviewed-by: Andrii Shyshkalov <a30c74fa30536fe7ea81ed6dec202e35e149e1fd@google.com>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go