Validate the routes in Route plugin submit

There is now a validation on the routes. It is not optimal as the modal closes, the error is printed in the policy form and the data are not saved. The user must re-add or re-edit the constraint. However, reworking that would be an overkill I think.

It will be available in the next release (2.0.2)

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