trivial: Initialize engine in fwupdtool install function
trivial: Initialize engine in fwupdtool install function

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