The installer found a couple configuration files, which live in /etc/weaved/services. However the message you received indicates that a different Weaved account was used to register these initially.
It is possible to have different services on a single device (e.g. Pi) registered to different accounts. There's nothing wrong with it, and it should work, but it's not a typical use case and if nothing else could be a little confusing.
You can delete these files from /etc/weaved/services and start over.