remote-info: Fix --show-metadata behavior
remote-info: Fix --show-metadata behavior

When the --show-metadata option is used with remote-info, the metadata
variable is never initialized, causing flatpak to print "(null)". This
commit makes sure the variable is properly initialized so the metadata
prints correctly.

Closes: #1313
Approved by: alexlarsson

handsome-feng/flatpak,flatpak/flatpak,handsome-feng/flatpak,flatpak/flatpak,matthiasclasen/flatpak,handsome-feng/flatpak,flatpak/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,handsome-feng/flatpak,matthiasclasen/flatpak,handsome-feng/flatpak,matthiasclasen/flatpak