The meeting text agenda page is now only in unlabelled UTC

[rjsparks]

/meeting/agenda.txt should probably render in meeting local time.
We should probably make
/meeting/agenda-utc.txt work again.
In any case, the resulting text should be explicit about what timezone it is being displayed in.

(Right now, it displays in UTC with a "Last changed at" at the top of the page in meeting local time...)