After uploading and attaching
the image as usual, you would then highlight the [ATTACH]######[/ATTACH]
code for the image, click on the globe "Insert Link" icon on the post editor toolbar to add and wrap the URL link around the attach code.
I'll add one to your post above now, so you can see when you edit it.
It'll have to be a smaller image in a post so as not to get the click to view larger image option that cancels the clickable link though.