4.1: Bug with log file clean-up.

With version 4.1 I enabled the file logging. I then noticed my PHP error_log with these:

[25-Oct-2015 21:53:19 America/Chicago] PHP Warning:  unlink((path)/wp-content/plugins/anti-spam/log/anti-spam-2014-10.log): No such file or directory in /(path)/wp-content/plugins/anti-spam/anti-spam-functions.php on line 38

So, I added a file_exists() check:

if (file_exists( $log_file_name_to_delete )) {
	  unlink( $log_file_name_to_delete );
   }

https://wordpress.org/plugins/anti-spam/