[Bug] l::set in only one language file

[mxub]

I just installed the langkit and then the static-translations plugin (via CLI)

it the says:

Undefined index: en

The Problem

I found the Problem. It is, that there is one l::set('pagination.prev') in de.php that is not in en.php

Possible Solution

Build all l::set from the default language and set the unset names in other languages to empyt

[rasteiner]

Merged the pr