Ticket created from upstream issue: https://github.com/389ds/389-ds-base/issues/6891

*Issue Description*

The jsonc library will crash if you call json_obj_add_str() with a nULL vlaue. So there are a lot of NULL checks in accesslog.c. It would be easier to just create a wrapper that will check for NULL and skip adding the string to the json object. Then we can remove all the NULL checks.