Spurious error message when changing default cover

When changing my default book cover on the Settings page, I get the (spurious) error message “No input file specified” after clicking one of the cover images. The default cover actually does change, so this is just a trivial blip.

Same bug as reported here: https://www.librarything.com/topic/365786

Looks like another incorrect URL to stats pages, should be https://www.librarything.com/stats/MEMBERNAME/covers after changing default book cover and instead it's going to https://www.librarything.com/profile/MEMBERNAME/stats/covers

Fixed.