Wrong behavior if server_audit_file_rotate_now set on command line or in config file

Users can set the system variable server_audit_file_rotate_now on the command-line and in the configuration file.

In fact it makes sense to specify the file_rotate_now=on at a startup. It would mean that server starts the new log after restart.

The problem though is that it doesn't work now as expected. If one does this - sets --server_audit_file_rotate_now=ON the rotation doesn't happen.

Instead the value of the file_rotate_now variable becomes 1. That should be fixed.