Provide an upgrade path from 2.0.x

Not sure if the maintainers want to add tests for this, but since the schema is really simple, I'd commit this without tests.

thanks for the MR.

merged and fixed. I also added a line to clear the 'prevnext_premission_check' value because it is used in 2.0.9 version of the module.

Automatically closed - issue fixed for 2 weeks with no activity.