Addresses crash scenario where too many cards were being loaded in a game.

- Too many iterations that fill up the server's memory trying to (1) render the deck hash and (2) building up a string of the deck contents

common/decklist.h

@@ -173,6 +173,7 @@ class DeckList : public QObject
 {
     Q_OBJECT
 private:
+    static constexpr unsigned int MAX_CARDS_TO_HASH = 100000;
     QString name, comments;
     QString deckHash;
     QMap<QString, SideboardPlan *> sideboardPlans;