/frame enabled without pictures => no error, no notice, no information.

[ildyria]

When there is no starred public pictures, the /frame should display an error instead of staying just black. I had to press F12 to discover why it was not working (though the error return by the server was quite explicit :) ).

[ildyria]

For anyone interested in giving it a jab, have a look at this:
https://github.com/LycheeOrg/Lychee-front/blob/master/scripts/frame/main.js