[rear-devel] [rear/rear] 36cf20: Update 900_clone_users_and_groups.sh

[Johannes Meixner]

  Branch: refs/heads/master
  Home:   https://github.com/rear/rear
  Commit: 36cf20e2d8bc136b334c2a70460b645afb770a24
      https://github.com/rear/rear/commit/36cf20e2d8bc136b334c2a70460b645afb770a24
  Author: Johannes Meixner <jsmeix at suse.com>
  Date:   2019-09-03 (Tue, 03 Sep 2019)

  Changed paths:
    M usr/share/rear/rescue/default/900_clone_users_and_groups.sh

  Log Message:
  -----------
  Update 900_clone_users_and_groups.sh

Skip empty user and group values,
cf. https://github.com/rear/rear/issues/2220