net-im/nheko: update to 0.9.2, latest upstream
Upstream has released a new mtxclient, and nheko chases that.
New dependency during build is asciidoc for the manpage.
Release notes are at:
https://github.com/Nheko-Reborn/mtxclient/releases/tag/v0.7.0
https://github.com/Nheko-Reborn/nheko/releases/tag/v0.9.2
It's a handful of bugfixes in mtxclient, and some UI changes in nheko.