Make PDT validation use the same rounding as the IPN validation.

includes/gateways/paypal/includes/class-wc-gateway-paypal-pdt-handler.php

@@ -106,7 +106,7 @@ public function check_response() {
 			update_post_meta( $order->get_id(), '_transaction_id', $transaction );
 
 			if ( 'completed' === $status ) {
-				if ( $order->get_total() !== $amount ) {
+				if ( number_format( $order->get_total(), 2, '.', '' ) !== number_format( $amount, 2, '.', '' ) ) {
 					WC_Gateway_Paypal::log( 'Payment error: Amounts do not match (amt ' . $amount . ')', 'error' );
 					/* translators: 1: Payment amount */
 					$this->payment_on_hold( $order, sprintf( __( 'Validation error: PayPal amounts do not match (amt %s).', 'woocommerce' ), $amount ) );