[PATCH 5 of 5] mail: convert encoding.encoding to sysstr

[Augie Fackler]

> On Aug 11, 2018, at 11:27 PM, Yuya Nishihara <yuya at tcha.org> wrote:
> 
> # HG changeset patch
> # User Yuya Nishihara <yuya at tcha.org>
> # Date 1534043768 -32400
> #      Sun Aug 12 12:16:08 2018 +0900
> # Node ID 1c137e0a33afe4d7e61325513d2518af8b93434a
> # Parent  a160d88772ff1da51160faa5cfdbd7ecdbcd07fa
> mail: convert encoding.encoding to sysstr

queued, thanks