Handle changed models between service versions

[canihavesomecoffee]

Currently, when replacing a service with a new version, there is no check in place that accounts for changes in the models that store the data in the database.

Ideally a check for this, and some way to upgrade from old to newer models should be in place.

Relevant code: https://github.com/PiPot/pipot-server/blob/70468cbad853ab3d3743f0e0d5831bfc4c0e36a9/mod_config/controllers.py#L375

[VertexC]

Fixed by PiPot/pipot-server#33