cosmetics in text version of sent mails by 2.12.2

[yeupou]

with 2.12.2, regarding second issue described in #245:

<a href="https://www.devuan.org/">https://www.devuan.org/</a> is transformed into https://www.devuan.org/ (https://www.devuan.org/)
<a href="https://www.devuan.org/os/announce/">fork of Debian without systemd</a> that into fork of Debian without systemd (https://www.devuan.org/os/announce/)that

In the first case, the repetition of the URL is redundant (not great for links in signatures, looks odd as it is redundant)
In the second case, the removal of the space just after the </a> breaks the output
That is cosmetics.

What is more annoying is that quotes of previous messages lacks > before each line. That breaks completely showing message history.

It is the result of htmlToPlain() from snappymail/v/2.12.0/static/js/app.js

[yeupou]

Thanks!