[Tails-l10n] Git rebase messes German special chars

Hi,

I recently translated a page and have it in a local page waiting for
getting published. It got changed now few days ago and I rebased the
branch to add the changes. But now the German special characters like
"ä,ü,ö and ß" are some weird character combinations (e.g. ä). How can
something like this happen and how do I prevent this or correct the problem?

Thanks and have a nice day!

spriver