Ticket 50128 - NS Stress fails without ipv6
    
    Bug Description: Docker for osx doesn't support ipv6, which
    means that in ipv4 only environments this test fails.
    
    We aren't trying to test ipv4/ipv6 here, only that NS handles
    load, so swapping to ipv4 is not a change to the test
    
    Fix Description: Change the PR_AF_INET6 to PR_AF_INET
    
    https://pagure.io/389-ds-base/issue/50128
    
    Author: William Brown <william@blackhats.net.au>
    
    Review by: ???