v2.6.4: Fix language check causing logging

The user language check loads a login shell to get the user's language. In certain cases, the login shell could generate some excess logging, which would cloud journalctl output. Now, the language check is only performed once.

This also means that updating the system language will now require a reboot to apply to handheld daemon.

Full Changelog: v2.6.3...v2.6.4