arbitrator-user and arbitrator-group is ignored

[jfriesse]

Config file contains possibility to change user/group of boothd when running as arbitrator. This is never used and always use default of site user/group (hacluster/haclient) or site-user/site-group config option.

This bug is long time behavior and changing to nobody/nobody would be probably unsafe so I would recommend to:

• change default for arbitrator to same as site = hacluster/haclient
• change documentation (again, default is hacluster/haclient)
• Fix arbitrator-user and arbitrator-group behavior