Wow, that's really weird. They seem to have specifically disabled it. You can use the userscript I just made for myself [1] as a workaround for now.
https://gist.github.com/selcuk/90ce1ce8b8d46c869efd6da24cde1...
https://gist.github.com/selcuk/90ce1ce8b8d46c869efd6da24cde1...