Issue 49939 - Fix ldapi path in lib389
    
    Lib389 uses a .replace rather than a path join, causing dirsrv to be replaced in
    the path. This breaks if the prefix is "/opt/dirsrv".
    
    This should use path join instead.
    
    https://pagure.io/389-ds-base/issue/49939
    
    Author: William Brown <william@blackhats.net.au>