We currently advertize the ISO-8859-1 charset is used when we
actually use UTF-8. Let's be consistent an advertize the truth.
This is the last patch in a serie which has brought the main, machine, run and
daily_report pages into clean html (according to https://validator.w3.org/nu).
I'm however wondering if there were any reason to use ISO-8859-1, thus this request for review.