setup-kolab on centos 7.2 doesn't check for FQDN in /etc/hostname

[Malte Schmidt-Tychsen]

When running setup-kolab, one of the programs being configured (I think 
amavisd) needs the FQDN when running uname -n. This only happens, when 
the FQDN is in /etc/hostname, which can be unusual, especially for 
people coming from Debian. When running setup-kolab in CentOS 7.2, the 
program would check and wouldn't start without this. Now the install 
starts, but fails if the FQDN isn't in /etc/hostname.