Revert "sync_stages: fix _VerifyMasterId to respect milestone_version"

This reverts commit f03233df8edc64eb35e86af6df18af9464969046.

This change seems to have broken all CQ bots.

BUG=chromium:612423

Change-Id: I296e6f7cc62484f207d9ff0cb8f10c986b108551
Reviewed-on: https://chromium-review.googlesource.com/344613
Reviewed-by: Shuhei Takahashi <nya@google.com>
Tested-by: Shuhei Takahashi <nya@google.com>
5 files changed