trivial: Allow running generic vfuncs in the tests without a GModule
trivial: Allow running generic vfuncs in the tests without a GModule

This makes it easier to set up test harness in the daemon self tests.

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