Pass instance provided in form builder to manager

[hansegucker]

In preference_form_builder there was passed an keyword argument called model, if set, to the registry's method manager. In the method the provided kwargs are passed directly to PreferencesManager, but there is already an argument model provided directly:

return PreferencesManager(registry=self, model=self.preference_model, **kwargs)

The only sensible argument that can passed is instance.

[Natureshadow]

Hi @EliotBerriot! Getting a bugfixed release would be most important to the AlekSIS project to make a very necessary release itself for schools that need it now. What can we do to make this happen?

[agateblue]

@Natureshadow you can expect a release today, unless something goes wrong ;)