fix managed-entries printing IPA not installed
    
    ipa-managed-entries would print "IPA is not configured on this system."
    even though this is not true if run as a normal user. Add check for
    root running the script.
    
    https://pagure.io/freeipa/issue/6928
    
    Reviewed-By: Pavel Vomacka <pvomacka@redhat.com>