[faiproject/fai] d4a1e5: prevent multiple IP ranges to appear in /etc/expor...

[Mrfai]

  Branch: refs/heads/master
  Home:   https://github.com/faiproject/fai
  Commit: d4a1e53b6290b450a38749c5a2b7d5ff0b4f8676
      https://github.com/faiproject/fai/commit/d4a1e53b6290b450a38749c5a2b7d5ff0b4f8676
  Author: Thomas Lange <lange at debian.org>
  Date:   2021-03-07 (Sun, 07 Mar 2021)

  Changed paths:
    M bin/fai-setup

  Log Message:
  -----------
  prevent multiple IP ranges to appear in /etc/exports, Closes: 984602