6.1.mos.deploy-deb job is failing because of incorrect fuel's hostname

Deployment fails because of incorrect postfix configuration at the build image step. Looks like fuel's hostname (nailgun..test.domain.local) has a wrong syntax. Logs from astute.log:
Stderr: "Postfix configuration was untouched. If you need to make changes, edit
/etc/postfix/main.cf (and others) as needed. To view Postfix configuration
values, see postconf(1).

After modifying main.cf, be sure to run '/etc/init.d/postfix reload'.

Running newaliases
newaliases: warning: valid_hostname: misplaced delimiter: nailgun..test.domain.local
newaliases: fatal: file /etc/postfix/main.cf: parameter myhostname: bad parameter value: nailgun..test.domain.local
dpkg: error processing package postfix (--configure):
 subprocess installed post-installation script returned error exit status 75
Errors were encountered while processing:
 postfix
E: Sub-process /usr/bin/dpkg returned an error code (1)"

Example log archive: http://osci-jenkins.srt.mirantis.net:8080/job/6.1.mos.deploy-deb/1730/artifact/fuel-qa/logs/fail_error_deploy_neutron_gre-2016_10_04__09_24_40.tar.xz archive

Setting Critical importance as this issue is a blocker for security bulletin.

Example job: http://osci-jenkins.srt.mirantis.net:8080/job/6.1.mos.deploy-deb/1730/