If an email reply ends with a markdown-style quote, email reply parser includes this quote in the fragment corresponding to the quoted email reply

For example:

```
Hi! I'm replying to an email! let me end it with a quote:

> this is a quote!

On Oct 9, 2011, at 3:47 PM, Maboo wrote:

> THIS IS THE ORIGINAL EMAIL!
> HI!
```

This produces the following fragments:

```
---
- !ruby/struct:EmailReplyParser::Fragment
quoted: false
signature: false
hidden: false
"@content": "Hi! I'm replying to an email! let me end it with a quote:"
"@lines":
- !ruby/struct:EmailReplyParser::Fragment
quoted: true
signature: false
hidden: true
"@content": |-

> this is a quote!

On Oct 9, 2011, at 3:47 PM, Maboo wrote:

> THIS IS THE ORIGINAL EMAIL!
> HI!
"@lines":
```

Maybe ERP should look for the `On Oct 9, 2011, at 3:47 PM, Maboo wrote` business as well as the angle bracket?

Beginne damit, das Problem anhand des E-Mail-Beispiels zu reproduzieren, und untersuche, wie der Parser Markdown-artige Zitate und die Antwortmarkierung „On Oct 9, 2011...“ verarbeitet. Erledigt ist es, wenn das abschließende Zitat nicht im sichtbaren Fragment enthalten ist, während die ursprünglich zitierte E-Mail verborgen bleibt.

Vom Indexierungsmodell aus dem Issue-Text verfasst.