[API] Add missing note about enabling API to UPGRADE-1.10 file
[API] Add missing note about enabling API to UPGRADE-1.10 file

diimpp/Sylius,antonioperic/Sylius,loic425/Sylius,Arminek/Sylius,Zales0123/Sylius,loic425/Sylius,Sylius/Sylius,Arminek/Sylius,SyliusBot/Sylius,101medialab/Sylius,diimpp/Sylius,antonioperic/Sylius,antonioperic/Sylius,lchrusciel/Sylius,Zales0123/Sylius,101medialab/Sylius,pamil/Sylius,Sylius/Sylius,Zales0123/Sylius,lchrusciel/Sylius,loic425/Sylius,lchrusciel/Sylius,Sylius/Sylius,SyliusBot/Sylius,pamil/Sylius,SyliusBot/Sylius,Arminek/Sylius,diimpp/Sylius,pamil/Sylius,101medialab/Sylius