Fix fdfcb09: for content service, fallback to TCP downloads when HTTP stalls (#12056)

src/network/network_content.h

@@ -113,6 +113,7 @@ public:
 	void Connect();
 	void SendReceive();
 	NetworkRecvStatus CloseConnection(bool error = true) override;
+	void Cancel();
 
 	void RequestContentList(ContentType type);
 	void RequestContentList(uint count, const ContentID *content_ids);