[PATCH v2] python: deprecated add_message calls index_file correctly and returns result

[Daniel Kahn Gillmor]

On Wed 2017-08-30 10:16:33 +0200, Gaute Hope wrote:
> The deprecated Database.add_message now calls the new index_file with
> correct number of arguments (without an extra `self`), and returns the
> tuple from index_file - as it used to do before.
>
> This change also adds a DeprecationWarning to the function.

lgtm.  thanks for fixing my bugs, Gaute.

       --dkg