Use nullable return type
Use nullable return type

In doctrine config the field flag is defined as nullable, so we should use nullable type in getter.

lchrusciel/Sylius,GSadee/Sylius,Sylius/Sylius,Brille24/Sylius,mbabker/Sylius,diimpp/Sylius,gorkalaucirica/Sylius,pjedrzejewski/Sylius,Arminek/Sylius,ezecosystem/Sylius,101medialab/Sylius,itinance/Sylius,gseidel/Sylius,Zales0123/Sylius,videni/Sylius,Sylius/Sylius,NeverResponse/Sylius,venyii/Sylius,foobarflies/Sylius,diimpp/Sylius,venyii/Sylius,Arminek/Sylius,venyii/Sylius,antonioperic/Sylius,mbabker/Sylius,videni/Sylius,bitbager/Sylius,gseidel/Sylius,pjedrzejewski/Sylius,GSadee/Sylius,bitbager/Sylius,Zales0123/Sylius,gorkalaucirica/Sylius,Brille24/Sylius,GSadee/Sylius,antonioperic/Sylius,videni/Sylius,gorkalaucirica/Sylius,itinance/Sylius,kayue/Sylius,pamil/Sylius,foobarflies/Sylius,foobarflies/Sylius,Sylius/Sylius,torinaki/Sylius,NeverResponse/Sylius,diimpp/Sylius,gseidel/Sylius,ezecosystem/Sylius,kayue/Sylius,antonioperic/Sylius,loic425/Sylius,videni/Sylius,Zales0123/Sylius,SyliusBot/Sylius,bitbager/Sylius,venyii/Sylius,gseidel/Sylius,bitbager/Sylius,101medialab/Sylius,SyliusBot/Sylius,Brille24/Sylius,SyliusBot/Sylius,ezecosystem/Sylius,NeverResponse/Sylius,torinaki/Sylius,foobarflies/Sylius,pamil/Sylius,NeverResponse/Sylius,mbabker/Sylius,lchrusciel/Sylius,itinance/Sylius,loic425/Sylius,ezecosystem/Sylius,torinaki/Sylius,pjedrzejewski/Sylius,Arminek/Sylius,torinaki/Sylius,lchrusciel/Sylius,101medialab/Sylius,itinance/Sylius,gorkalaucirica/Sylius,kayue/Sylius,pjedrzejewski/Sylius,mbabker/Sylius,pamil/Sylius,loic425/Sylius,Brille24/Sylius