Fix#4484 :Allow unselect an item when multiselect is False
Fix#4484 :Allow unselect an item when multiselect is False

tony/kivy,inclement/kivy,rnixx/kivy,matham/kivy,Cheaterman/kivy,matham/kivy,rafalo1333/kivy,jkankiewicz/kivy,kived/kivy,janssen/kivy,janssen/kivy,kived/kivy,autosportlabs/kivy,KeyWeeUsr/kivy,janssen/kivy,Cheaterman/kivy,matham/kivy,manthansharma/kivy,Cheaterman/kivy,LogicalDash/kivy,Cheaterman/kivy,tony/kivy,kivy/kivy,jkankiewicz/kivy,KeyWeeUsr/kivy,bionoid/kivy,manthansharma/kivy,kivy/kivy,jegger/kivy,matham/kivy,rnixx/kivy,autosportlabs/kivy,janssen/kivy,bionoid/kivy,kivy/kivy,LogicalDash/kivy,tony/kivy,autosportlabs/kivy,LogicalDash/kivy,inclement/kivy,rafalo1333/kivy,jegger/kivy,rafalo1333/kivy,KeyWeeUsr/kivy,manthansharma/kivy,jegger/kivy,rnixx/kivy,jkankiewicz/kivy,inclement/kivy,akshayaurora/kivy,jkankiewicz/kivy,manthansharma/kivy,jegger/kivy,KeyWeeUsr/kivy,bionoid/kivy,akshayaurora/kivy,LogicalDash/kivy,kived/kivy,akshayaurora/kivy,bionoid/kivy