Fixes #5026: Documentation for installing a relay server uses a group only available on RHEL/CentOS
Merge pull request #67 from jooooooon/bug_5026/documentation_for_installing_a_relay_server_uses_a_group_only_available_on_rhel_centos

Fixes #5026: Documentation for installing a relay server uses a group on...
Merge branch 'branches/rudder/2.9' into branches/rudder/2.10
Merge branch 'branches/rudder/2.10' into branches/rudder/2.11