trivial: Do the fwupdmgr network setup in a new function
trivial: Do the fwupdmgr network setup in a new function

This is for future use by other commands.

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