[zanata/zanata-platform] 6dafa9: Use SLF4J MDC, not Log4j (#488)

[GitHub]

  Branch: refs/heads/release
  Home:   https://github.com/zanata/zanata-platform
  Commit: 6dafa9125734265a05817417626513bfe9662608
      https://github.com/zanata/zanata-platform/commit/6dafa9125734265a05817417626513bfe9662608
  Author: Sean Flanigan <sflaniga at redhat.com>
  Date:   2017-08-23 (Wed, 23 Aug 2017)

  Changed paths:
    M server/services/src/main/java/org/zanata/security/UsernameLoggingFilter.java

  Log Message:
  -----------
  Use SLF4J MDC, not Log4j (#488)