[NTG-context] \WORD regression

\starttext \WORD{größer} \stoptext \WORD used to handle "ß" correctly, i.e. convert it to "SS"; now it makes "sS". (If the current font contains an uppercase ß that would be even better, but those are rare). I can’t tell when it changed (some LMTX versions ago) and can’t check MkIV, since "mtxrun --generate --luatex" doesn’t work. Hraban