Border gitch

- [x] I have read through https://github.com/junegunn/fzf.vim/blob/master/README.md
- [x] I have read through https://github.com/junegunn/fzf/blob/master/README-VIM.md
- [x] I have read through the manual page of fzf (`man fzf`)
- [x] I have searched through the existing issues

When I run any fzf command I get this weird strings of characters instead of what should be my fzf border.

fzf, fzf-vim and vim are up to date
This is my minimal vimrc:
```
call plug#begin()
Plug 'junegunn/fzf', { 'dir': '~/.fzf', 'do': './install --all' }
Plug 'junegunn/fzf.vim'
let g:fzf_layout = { 'window': { 'width': 0.5, 'height': 0.5 } }
call plug#end()
```
vim --version:
```
VIM - Vi IMproved 8.2 (2019 Dec 12, compiled Apr 18 2020 18:18:30)
Included patches: 1-595
```