This should at least mitigate our build error to only occur in v8 anymore.
Unfortunately we can't use v8 from nixpkgs right now, so we're going to put out
our sledgehammer in the next commit. Meanwhile, it doesn't hurt to get rid of
the bundled protobuf library, so let's do it.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>