Cart update success message displayed for empty discount code input

[Kriz83]

Sylius version affected: 1.11., 1.12.

Description
Given:

• there is an item in the cart

Steps to reproduce

• Click on the "Apply coupon" button (leave the field with the code blank)
  
• Instead of the Coupon code is invalid. message there is a flash message Success - The cart has been successfully updated
  current:
  
  expected:
  

[Rafikooo]

Hello @Kriz83, thank you for submitting the issue. We acknowledge the validity of your concern. Currently, we have other pressing matters to address. However, if you are interested in contributing to Sylius on your own, we would greatly appreciate it. One simple solution would be to deactivate the button when input field is empty 🕺