Refresh resolvers after DNS install
    
    Server framework calls acutil.res_send() to send DNS queries used
    for various DNS tests. However, once acutil is imported it does
    not change its list of configured resolvers even when
    /etc/resolv.conf is changed. This may lead to unexpected
    resolution issues.
    
    We should at least reload httpd when we change /etc/resolv.conf to
    point to FreeIPA nameserver to force a new import of acutil and
    thus workaround this bug until it is resolved in authconfig.
    
    https://fedorahosted.org/freeipa/ticket/2481