[PATCH STABLE] ui: flush before prompting for input with readline

[Yuya Nishihara]

On Sat, 02 Nov 2019 15:35:18 -0700, Gregory Szorc wrote:
> # HG changeset patch
> # User Gregory Szorc <gregory.szorc at gmail.com>
> # Date 1572734019 25200
> #      Sat Nov 02 15:33:39 2019 -0700
> # Branch stable
> # Node ID 584cfb5d3d3c5cc78514e8ed8f688b52fd60cf47
> # Parent  5fae970ebefab080585d06d7783e9bcb424b09e9
> ui: flush before prompting for input with readline

Queued for stable, thanks.