49884 - Improve nunc-stans test to detect socket errors sooner
    
    While testing on a fresh machine (without ipv6) I noticed the ns test
    would fail. This led me to improve the state of the ns stress test
    code to remove the legacy atomic, and check assertions of the sockets.
    
    https://pagure.io/389-ds-base/pull-request/49884
    
    Author: William Brown <william@blackhats.net.au>