dfu: Guess the transfer size if it is not specified
dfu: Guess the transfer size if it is not specified

vathpela/fwupd,hughsie/fwupd,fwupd/fwupd,vathpela/fwupd,fwupd/fwupd,hughsie/fwupd,superm1/fwupd,vathpela/fwupd,superm1/fwupd,hughsie/fwupd,vathpela/fwupd,hughsie/fwupd,fwupd/fwupd,superm1/fwupd,fwupd/fwupd