trivial: debian: Pass -a into dh_missing (Closes: #906357)
trivial: debian: Pass -a into dh_missing (Closes: #906357)

dpkg-buildpackage -A does the architecture independent builds and
is failing due to mistakingly seeing a file that is not installed.

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