fixes fee increment calculation for loan payment

Author: Tapanito

src/xrpld/app/tx/detail/LoanPay.cpp

@@ -109,8 +109,9 @@ LoanPay::calculateBaseFee(ReadView const& view, STTx const& tx)
     NumberRoundModeGuard mg(
         tx.isFlag(tfLoanOverpayment) ? Number::upward : Number::downward);
     // Estimate how many payments will be made
-    Number const numPaymentEstimate =
-        static_cast<std::int64_t>(amount / regularPayment);
+    Number const numPaymentEstimate = std::min(
+        static_cast<std::int64_t>(amount / regularPayment),
+        Lending::loanMaximumPaymentsPerTransaction);
 
     // Charge one base fee per paymentsPerFeeIncrement payments, rounding up.
     Number::setround(Number::upward);