Re-starting syslog-ng with the supplied config file logs
WARNING: Configuration file format is too old, syslog-ng is running in compatibility mode. Please update it to use the syslog-ng 3.16 format at your time of convenience. To upgrade the configuration, please review the warnings about incompatible changes printed by syslog-ng, and once completed change the @Version header at the top of the configuration file.;
While syslog-ng appears to run, the message can be distracting for users trying to properly configure on their system.
https://github.com/openwrt/packages/blob/master/admin/syslog-ng/files/syslog-ng.conf
See also https://forum.openwrt.org/t/system-log-level-with-logd/16798/10?u=jeff