Prevent service restart failures in ipa-replica-install
    
    Call restart() methods of appropriate services instead of calling
    the system service restart command directly as service() method
    has a capability to wait until the service is fully up. Without
    this patch ipa-replica-install crashed on F-16 because krb5kdc
    service was started before dirsrv service was fully up.
    
    https://fedorahosted.org/freeipa/ticket/2139