Fix crash in Website::getGames
JSON value for updates can be null in some cases. For example when user owns a dlc but not the base game.
This caused a crash due to std::stoi throwing std::invalid_argument exception
Origin: upstream, 3.2, commit:
22f47de4fcd8cd7ecc2a89fbb25f94efb1b3f743
Gbp-Pq: Name Fix-crash-in-Website-getGames.patch