[zanata/zanata-platform] fdff83: fix more warning

[GitHub]

  Branch: refs/heads/fix-master
  Home:   https://github.com/zanata/zanata-platform
  Commit: fdff8397e3da7d4fd5609109d29cb4cb496f7d9e
      https://github.com/zanata/zanata-platform/commit/fdff8397e3da7d4fd5609109d29cb4cb496f7d9e
  Author: Patrick Huang <pahuang at redhat.com>
  Date:   2017-05-08 (Mon, 08 May 2017)

  Changed paths:
    M server/zanata-model/src/main/java/org/zanata/model/HAccountActivationKey.java

  Log Message:
  -----------
  fix more warning