Fix unknown type attachment

Co-authored-by: Samantaz Fox <coding@samantaz.fr>

src/invidious/channels/community.cr

@@ -217,11 +217,13 @@ def fetch_channel_community(ucid, continuation, locale, format, thin_mode)
                       .as(SearchPlaylist)
                       .to_json(locale, json)
                   else
+                    json.object do
                       json.field "type", "unknown"
                       json.field "error", "Unrecognized attachment type."
                     end
                   end
                 end
+              end
 
               if comments && (reply_count = (comments["backstageCommentsRenderer"]["moreText"]["simpleText"]? ||
                                              comments["backstageCommentsRenderer"]["moreText"]["runs"]?.try &.[0]?.try &.["text"]?)