src/conf.py: use ISO 8601 in reply.format.time.
src/conf.py: use ISO 8601 in reply.format.time.

If I read the code for Time correctly, it uses this value by default. I
think that this fixes #701 .

ProgVal/Limnoria-test,ProgVal/Limnoria-test,Ban3/Limnoria,Ban3/Limnoria