If you do not use v2.0.2 or higher, you will not have online.php.
But the changes done to online.php are very very minor, and have absolutely no influence on the sent-to-friend functionality. You can safely install this hack, and skip step 2.
EDIT:
Just so you understand. The changes in online.php are done to make it so that when a user is on the new page, it won't show a "Unknown location" message, but a "Sending a page to friend" message. Since you don't use online.php, there's no need in this.