Explanation
You can change your backend configuration at any time. You can change both the configuration itself as well
as the type of backend (for example from "consul" to "s3").
Terraform will automatically detect any changes in your configuration and request a reinitialization. As part of
the reinitialization process, Terraform will ask if you'd like to migrate your existing state to the new
configuration. This allows you to easily switch from one backend to another.
https://www.terraform.io/docs/backends/config.html#changing-configuration