libostree: Ensure progress keys are all always set
libostree: Ensure progress keys are all always set

If one of the progress keys is set in a pull operation, a ::changed
signal is emitted on the progress object, and the callback for that
could query any of the progress keys — so they all need to be set,
otherwise we get an assertion failure in ostree_async_progress_get() due
to a named key not existing.

Spotted by Dan Nicholson in PR #819.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Closes: #835
Approved by: cgwalters

GNOME/ostree,GNOME/ostree,GNOME/ostree,GNOME/ostree,GNOME/ostree