A 344MB error_log and as well as a processed access_ssl_log for forum.mupdvig.tk have been removed. The messages were basically a flood of access denied errors from the IP of an abusive indexing bot.
You can set up log rotation to prevent this. I've set it for you to no more than five 10MB files, but you may want to change it. To do that, in Plesk under the affected domain you can go to Logs->Manage Log Files->Log Rotation and set a max file size and number of logs to keep.