shell: Ignore G_IO_ERROR_CANCELLED errors
Just as we ignore GS_PLUGIN_ERROR_CANCELLED
errors, ignore
G_IO_ERROR_CANCELLED
errors.
Realistically, we are never going to manage to find every call site
which could return G_IO_ERROR_CANCELLED
and convert all of those
errors to GS_PLUGIN_ERROR_CANCELLED
on an ongoing basis.
Signed-off-by: Philip Withnall withnall@endlessm.com