Hi Not the maintainer here, but given coturn is going to be removed from testing otherwise I quickly looked at this. In default install this does not seem to be a problem, turnserver uses the syslog option and logfile settings are commented out.
So while there is probably some room of improvement (e.g. introducing a logrotate file, when logfile, vebose and single-log are enabled) the severity of RC might not be warranted. Regards, Salvatore