This reverts commit bfa05c83.

Reason for revert: breaks bot bootstrap

Original change's description:
> update_depot_tools: make cipd_bin_setup failures fatal
> 
> This should make them more noticeable.
> 
> Bug: 762568
> Change-Id: Ibd4ca4dc34d36aec5773d28454d134c909cc78dc
> Reviewed-on: https://chromium-review.googlesource.com/653157
> Reviewed-by: Daniel Jacques <dnj@chromium.org>
> Commit-Queue: Paweł Hajdan Jr. <phajdan.jr@chromium.org>

TBR=phajdan.jr@chromium.org,dnj@chromium.org

Change-Id: I14e8aae77beca52ebbd21567e2ea20954e2b34d8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 762894, 762568
Reviewed-on: https://chromium-review.googlesource.com/654977Reviewed-by: Paweł Hajdan Jr. <phajdan.jr@chromium.org>
Commit-Queue: Paweł Hajdan Jr. <phajdan.jr@chromium.org>