The only line missing is: log_file=/var/log/rbfeeder.log.
I dont think having the line starting with "log_file=" is necessary, as this is default setting. However you can check if the log file exists in folder /var/log/ and logs are written to it by following command.
sudo nano /var/log/rbfeeder.log
Later addition:I feel that you dont know how to copy-past text to a file through PuTTY, that is why you did not understand what wiedehopf told, although that was easy. I am attaching an image which explains how to copy-paste text to a file through PuTTY.