delete ~bzr-nightly-ppa?

[Martin Pool]

<https://launchpad.net/~bzr-nightly-ppa/+archive/ppa> still exists,
but it seems to be strictly older than
<https://launchpad.net/~bzr/+archive/daily>.

The former was created before Launchpad allowed more than one ppa per
person/team.  Maybe we should just delete it now?  I think it's better
not to have people think they're getting nightly builds but actually
not be.

I have access to delete it, so I just want to check if anyone objects.

Martin