Hi,
Thanks for the bug report.
I've just fixed this in my copy so it will be fixed in the next release, it is a handled error so it isn't causing any problems other than older log entries are not being deleted by default.
I've just updated the article Logging to the Database with some additional config settings that were not documented. You can disable the default behavior of deleting older log items on application start if you want to, though it is ok to leave it alone and ignore that error, it will stop happening after you upgrade to the next release. I must have that disabled on this site as I'm using MySql and database logging and haven't seen that in my log, but I review my log every day and clear the log after I review it. This setting to make it automatically clear the old logs is just because if not attended to it can really accumulate over time.
Best,
Joe