[Bug] "empty" param when with_popup=false

[postrockreverb]

To reproduce

Steps to reproduce the behavior:

1. Set with_popup=false

require('renamer').setup {
  with_popup = false
}

2. Run lua require('renamer').rename({empty = false})
3. Get cmd prompt "Rename "err" to: "

Expected behavior

3. Get cmd prompt "Rename "err" to: err"