[libvirt] [PATCH] build: fix incremental autogen.sh when no AUTHORS is present

[Eric Blake]

> > Commit 71d1256 tried to fix a problem where rebasing an old
> > branch on top of newer libvirt.git resulted in automake failing
> > because of a missing AUTHORS file.  However, while the fix
> > worked for an incremental 'make', it did not work for someone
> > that directly reran './autogen.sh'.  Reported by Laine Stump.
> >

> 
> My local tree isn't in a state that I can conveniently test it right
> now, but it looks correct to me. ACK.

Thanks; pushed.

-- 
Eric Blake   eblake at redhat.com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org