For a few months now many people have been asking how translations are integrated within phpList. Honestly, it is amazing that you spend some time to translate phpList in your native language!!
As you might have already noticed, when you translate strings on a certain language they don’t get immediately included in the upcoming version. For now, we are working in resolving this and everything that is blocking the immediate integration of the translated strings in every release.
If you want to translate phpList please do so on translate.phplist.org and not on GitHub. translate.phplist.org is the place where all translations (for every language) should live.
The reason why phpList has such a rapid development cycle is to be able to offer back to the community users a software that includes their contributions! Hopefully, this will get resolved soon.