on upgrade to 6.0. (Not extensively tested yet)
We do this for two reasons:
1) the config file layout is completely different, it's error-prone
and tedious to force the user to manually transfer their customizations
on upgrade;
2) if there are user modifications to the config file, an upgrade triggered
remotely via piaware will prefer to keep the original config file intact
rather than installing the new version, and the old version just won't
work correctly with the new infrastructure.