As recommended in https://docs.docker.com/develop/develop-images/dockerfile_best-practices/#sort-multi-line-arguments



  "This helps to avoid duplication of packages and make the
  list much easier to update. This also makes PRs a lot easier
  to read and review."

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20180818015344.797-2-f4bug@amsat.org>
Signed-off-by: Fam Zheng <famz@redhat.com>