Quoting one line will quote the following line as well unless there's an empty line in-between

### Description

When quoting a line in the message to be sent by prepending the > character, the following line will also be quoted unless it's an empty newline.

### Steps to reproduce

Write a message line the following:
```
> This is the line I want to quote
This is a line I don't want quoted.
```

What I expect is to see only the first line quoted. What I see instead is:


A work-around is inserting an empty line in-between, like so:

```
> This is the line I want to quote

This is a line I don't want quoted.
```

This trips me up constantly...

### Version information

- **Platform**: desktop app

For the desktop app:

- **OS**: Linux openSuse tumbleweed
- **Version**: 1.7.16