a15fdea installer: Stop adding distro-specific NTP servers into ntp.conf

Authored and Committed by dkupka 7 years ago
    installer: Stop adding distro-specific NTP servers into ntp.conf
    
    Distribution packaged ntpd has servers preconfigured in ntp.conf so
    there's no point in trying to add them again during FreeIPA server
    installation.
    Also fix the code to always put fudge line right after the local server
    line as required by ntpd.
    
    https://fedorahosted.org/freeipa/ticket/6486
    
    Reviewed-By: Petr Spacek <pspacek@redhat.com>