Regardless of the settings within the config file, the url created in the m3u/xspf/vclt files is still in HTTP.

It looks to be due to the following lines in /src/fserve.c (lines 476 till 493) where the http is hardcoded:

        if (host == NULL)
        {
            config = config_get_config();
            snprintf (httpclient->refbuf->data + ret, BUFSIZE - ret,
                    "http://%s:%d%s\r\n",
                    config->hostname, config->port,
                    sourceuri
                    );
            config_release_config();
        }
        else
        {
            snprintf (httpclient->refbuf->data + ret, BUFSIZE - ret,
                    "http://%s%s\r\n",
                    host,
                    sourceuri
                    );
        }