[PATCH] tdb2: Fix typo in TDB1_porting.txt

[Rusty Russell]

On Mon, 14 May 2012 18:57:36 +0400, Kirill Smelkov <kirr at mns.spb.ru> wrote:
> Judging by code it's tdb1, where you needed to free old key's dptr
> manually.
> 
> Signed-off-by: Kirill Smelkov <kirr at mns.spb.ru>

Thanks, I've applied this manually to my branch where I'm busy renaming
TDB2 to ntdb.

Thanks!
Rusty.