Fix updating pending payment

Check if payment actually have an adjustment before trying to update it

engines/order_management/app/services/order_management/order/updater.rb

@@ -240,19 +240,25 @@ module OrderManagement
         return unless order.state.in? ["payment", "confirmation", "complete"]
         return unless order.pending_payments.any?
 
+        @payment = order.pending_payments.first
+        return update_payment if @payment.adjustment.nil?
+
         # Update payment tax fees if needed
-        payment = order.pending_payments.first
-        new_amount = payment.payment_method.compute_amount(payment)
-        if new_amount != payment.adjustment.amount
-          update_payment_adjustment(payment.adjustment, new_amount)
+        new_amount = @payment.payment_method.compute_amount(@payment)
+        if new_amount != @payment.adjustment.amount
+          update_payment_adjustment(new_amount)
         end
 
-        # Update payment with correct amount
-        payment.update_attribute :amount, order.total
+        update_payment
       end
 
-      def update_payment_adjustment(adjustment, amount)
-        adjustment.update_attribute(:amount, amount)
+      def update_payment
+        # Update payment with correct amount
+        @payment.update_attribute :amount, order.total
+      end
+
+      def update_payment_adjustment(amount)
+        @payment.adjustment.update_attribute(:amount, amount)
 
         # Update order total to take into account updated payment fees
         update_adjustment_total