summary: Don't cache summary if none was returned
summary: Don't cache summary if none was returned

ostree_repo_remote_fetch_summary can set out_summary to NULL but
still return TRUE according to the documentation, so don't assume
that *out_summary will always be set.

handsome-feng/flatpak,GeorgesStavracas/flatpak,GeorgesStavracas/flatpak,handsome-feng/flatpak,matthiasclasen/flatpak,GeorgesStavracas/flatpak,GeorgesStavracas/flatpak,flatpak/flatpak,handsome-feng/flatpak,flatpak/flatpak,amigadave/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,flatpak/flatpak,handsome-feng/flatpak,amigadave/flatpak,matthiasclasen/flatpak,amigadave/flatpak,amigadave/flatpak,matthiasclasen/flatpak,GeorgesStavracas/flatpak,handsome-feng/flatpak,flatpak/flatpak,flatpak/flatpak