Throw an error toast if the comic has no images (should only happen when something in the file is broken)

js/comics.js

@@ -228,6 +228,12 @@ function showComic(comic, name) {
                        redirectToLogin();
                        return;
                     }
+                    if ( data.images.length == 0 ) {
+                       toastr.remove();
+                       toastr.error("There doesn't seem to be any images in this comic. Please contact the admin!", "Comics is empty", {timeOut: 8000});
+                       return;
+                    }
+                    toastr.remove();
                     lightbox = SimpleLightbox.open({
                        items: data.images,
                        captions: data.captions,