[Koha] Updating the languages

[Frédéric Demians]

> Updating Koha I get the following:
>
> /usr/share/koha/opac/htdocs/opac-tmpl/prog/en/: Input must be a directory.
> (Symbolic links are not supported at the moment)
>
> when my languages are updated.
>
> I'm using 3.20.01 installed / updated using packages for debian.

'prog' OPAC theme is deprecated and replaced by 'bootstrap' theme. Try
removing  /usr/share/koha/opac/htdocs/opac-tmpl/prog