Clarify GPL 2.1 or later
https://invent.kde.org/network/kio-extras/-/blob/master/smb/smburl.h claims to be GPL 2.1 or later, which is at odds with the nonexistance of GPL 2.1
https://invent.kde.org/network/kio-extras/-/blob/master/smb/smburl.h claims to be GPL 2.1 or later, which is at odds with the nonexistance of GPL 2.1