fixed Binance.OnGetCompletedOrderDetailsAsync() bug

- fixes #398

Author: vslee

ExchangeSharp/API/Exchanges/Binance/ExchangeBinanceAPI.cs

@@ -610,10 +610,10 @@ protected override async Task<IEnumerable<ExchangeOrderResult>> OnGetCompletedOr
             {
                 Dictionary<string, object> payload = await GetNoncePayloadAsync();
                 payload["symbol"] = marketSymbol;
-                if (afterDate != null)
-                {
-                    payload["timestamp"] = afterDate.Value.UnixTimestampFromDateTimeMilliseconds();
-                }
+				if (afterDate != null)
+				{
+					payload["startTime"] = afterDate.Value.UnixTimestampFromDateTimeMilliseconds();
+				}
                 JToken token = await MakeJsonRequestAsync<JToken>("/myTrades", BaseUrlPrivate, payload);
                 foreach (JToken trade in token)
                 {