PATCH inn-2.4.5 : fixes for buffindex storage method

[Kirill Berezin]

Hi Julien.
> Already present in INN 2.5.0:
>
>  static OVBUFF *ovbufftab = NULL;
>
> (not the suggested (OVBUFF*)NULL but it does not matter).
It looks like the tarball at ftp.isc.org is a little bit outdated, but 
it's great if this variable is set to zero in some way.
> By the way, I also see that buffindexed is more robust with INN 2.5.0:
> ...
>
Yes it is a really great improvement, I have seen server both expiring 
old articles and receiving new at regular rate with a little backlog at 
feeder.
> Have a nice week-end,
Thanks.