builtin-pack-objects: don't fail, if delta is not possible
builtin-pack-objects: don't fail, if delta is not possible

If builtin-pack-objects runs out of memory while finding
the best deltas, it bails out with an error.

If the delta index creation fails (because there is not enough memory),
we can downgrade the error message to a warning and continue with the
next object.

Signed-off-by: Martin Koegler <ea56f0187842ce0af18f0283b5f003697482ffdd@auto.tuwien.ac.at>
Signed-off-by: Junio C Hamano <dc50d1021234060e53ec42a77d526afa2fe07479@cox.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git