minor typo

spring-webflow-reference/src/views.xml

@@ -471,7 +471,7 @@ public class BookingAction {
            bookingService.make(booking);
            return true;
        } catch (RoomNotAvailableException e) {
-           context.addMessage(builder.error().
+           context.addMessage(new MessageBuilder().error().
                .defaultText("No room is available at this hotel").build());
            return false;
        }