Interactively-entered passwords were run through NFKC Unicode
normalization before being obscured, which silently rewrote characters
such as ª (U+00AA) to a. The obscured password then revealed to
something different from what the user typed confusing everyone.
Normalization is only needed for the config encryption master
password, so apply it there (in SetConfigPassword) rather than in the
shared checkPassword used for backend password options.