googleanalytics parameters must be of category 'system'

Upgrade verifier says: your google analytics properties will be reset to their default values. We don't want that, so I suggest to change their category to 'system'.

hippo-connect has an additional property 'privateKey', which upgrade verifier claims to delete. This property is not part of the YAML Source (hence the 'delete'). Check if this is an old, outdated property, or if we should add it to the YAML Source (as system, too).