Ctrl-R deletes last ouput line under gnu screen when PS1 contains \u@\h

- [x] I have read through the manual page (`man fzf`)
- [x] I have the latest version of fzf
- [x] I have searched through the existing issues

## Info

- OS
- [x] Linux
- [ ] Mac OS X
- [ ] Windows
- [ ] Etc.
- Shell
- [x] bash
- [ ] zsh
- [ ] fish

## Problem / Steps to reproduce

When running under gnu screen, if PS1 contains \u@\h, Ctrl-R history selection deletes last output line.

To reproduce:

export PS1='\u@\h'
pwd
Ctrl-R -> select pwd, last output of pwd will be deleted

Workaround (enclose \h with \[\]):

export PS1='\[\u\]@\h'

This might not be a problem of fzf at all --- running under tmux has no problem.

Start by reproducing the Ctrl-R history selection under GNU screen with bash and PS1 set to '\u@\h', then compare the same steps under tmux and with the documented workaround. Trace whether the deleted output is caused by fzf or terminal interaction; done means selecting history no longer removes the last output line under the reported setup.

Written by the indexing model from the issue text.