Move up-to this revision in the upstream:

  commit de1e8c7bfe7c875ea284b55040e8f3cd3a56fcc2
  Author: Abhinav Sharma <abhinavsharma@fb.com>
  Date:   Thu Aug 23 14:34:39 2018 -0700

      Log updates to semi-sync whitelist in the error log

      Summary:
      Plugin variable changes are not logged in the error log even when
      log_global_var_changes is enabled. Logging updates to whitelist will help in
      debugging.

      Reviewed By: guokeno0

      Differential Revision: D9483807

      fbshipit-source-id: e111cda773d