doc: tweaked licence wording in sources/guide/licensing.rst
doc: tweaked licence wording in sources/guide/licensing.rst

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