There's no automatic way to detect the keyboard layout with SFML (yet).
However, as long as you provide a way to change key bindings, it will be on a good track. Yes, it might be annoying that one has to adjust the keys when starting the game, but it's also not very uncommon. For example, I don't know many games who will detect that my Swiss-German keyboard layout has Y and Z swapped. It's annoying that I have to change it, but as long as I can change it, it remains a minor annoyance.
Depending on how many keys you use, I've also seen games ask you to press the relevant keys at the start of the game and will automatically bind them. This fulfills two purposes, you don't have to select a default set of key bindings and you're already teaching the user all the available keys and actions. Of course this doesn't work for everything.