Fix the self tests when using glib2 >=2.59.0
Fix the self tests when using glib2 >=2.59.0

Replace the non-breaking space with a traditional space rather than changing
the expected output with #ifdef to allow running the tests with a daemon
compiled against an older glib2 version.

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