It was never in Catalog Settings. It always has been, and still is located in, the dialog box that pops up when you exit Lightroom and asks you to make a backup.
In the future, So people don't have to download the image you have attached, please use the Insert Photos icon found in the Tool Bar of the Post and Reply text entry dialog window as pictured below.
If you can please Edit your post to remove the Attached screen shot and Include it in the body of the text of your post.
You do that by Clicking the "More..." link at the bottom of your post, Selecting "Edit Message" and then use the "Insert Photos" icon in the tool bar at the top of the Post/Reply/Edit dialog box.
If you can't edit your post please include the screen shot you attached to a new reply to this conversation.
The Insert Photos icon is this one in the Tool Bar.
Editing the post is not possible. For future posts, I will embed the image. Thanks for the help