[zanata/zanata-server] 13ebe6: Add release-notes on new system property

[GitHub]

  Branch: refs/heads/ZNTA-855-enforce-username
  Home:   https://github.com/zanata/zanata-server
  Commit: 13ebe695372451c2028c7094fe7b95c7f8f8df5e
      https://github.com/zanata/zanata-server/commit/13ebe695372451c2028c7094fe7b95c7f8f8df5e
  Author: Alex Eng <aeng at redhat.com>
  Date:   2016-05-20 (Fri, 20 May 2016)

  Changed paths:
    M docs/release-notes.md

  Log Message:
  -----------
  Add release-notes on new system property