- Added currency.transactionsLifetime which controls auto-deletion of currency transactions from the database

- Updated changelog

src/NadekoBot/Modules/Gambling/GamblingConfig.cs

@@ -77,6 +77,10 @@ public class CurrencyConfig
 
     [Comment(@"What is the name of the currency")]
     public string Name { get; set; } = "Nadeko Flower";
+
+    [Comment(@"For how long will the transactions be kept in the database (curtrs)
+Set 0 to disable cleanup (keep transactions forever)")]
+    public int TransactionsLifetime { get; set; } = 0;
 }
 
 [Cloneable]