Fix extractor for channel community cursor

src/invidious/channels.cr

@@ -808,11 +808,23 @@ def produce_channel_community_continuation(ucid, cursor)
 end
 
 def extract_channel_community_cursor(continuation)
-  cursor = URI.decode_www_form(continuation)
+  object = URI.decode_www_form(continuation)
     .try { |i| Base64.decode(i) }
     .try { |i| IO::Memory.new(i) }
     .try { |i| Protodec::Any.parse(i) }
-    .try { |i| Protodec::Any.cast_json(i["80226972:0:embedded"]["3:1:base64"].as_h) }
+    .try { |i| i["80226972:0:embedded"]["3:1:base64"].as_h }
+
+  if object["53:2:embedded"]?.try &.["3:0:embedded"]?
+    object["53:2:embedded"]["3:0:embedded"]["2:0:string"] = object["53:2:embedded"]["3:0:embedded"]
+      .try { |i| i["2:0:base64"].as_h }
+      .try { |i| Protodec::Any.cast_json(i) }
+      .try { |i| Protodec::Any.from_json(i) }
+      .try { |i| Base64.urlsafe_encode(i, padding: false) }
+
+    object["53:2:embedded"]["3:0:embedded"].as_h.delete("2:0:base64")
+  end
+
+  cursor = Protodec::Any.cast_json(object)
     .try { |i| Protodec::Any.from_json(i) }
     .try { |i| Base64.urlsafe_encode(i) }