test push has been failing to deploy servers.

I manually run "/usr/local/autotest//site_utils/deploy_server.py -x --afe=chromeos-staging-master2.hot.corp.google.com --update_push_servers" and it reported the error

Traceback (most recent call last):
  File "/usr/local/autotest/site_utils/deploy_server_local.py", line 541, in <module>
    sys.exit(main(sys.argv[1:]))
  File "/usr/local/autotest/site_utils/deploy_server_local.py", line 533, in main
    use_chromite_master=behaviors.update_push_servers)
  File "/usr/local/autotest/site_utils/deploy_server_local.py", line 364, in run_deploy_actions
    skip_service_status=skip_service_status)
  File "/usr/local/autotest/site_utils/deploy_server_local.py", line 334, in restart_services
    raise UnstableServices(unstable_services)
__main__.UnstableServices: ['server_db_sync']