Set up correct API URLs

[simonihmig]

We should add a prompt to query for the correct API URLs, whcih are currently wrong here:

• https://github.com/kaliber5/k5-ember-boilerplate/blob/d2040e764f78eb8abfba6bba203b5f4927b2e92e/blueprints/%40kaliber5/k5-ember-boilerplate/files/.env-prod-normal#L4 (and other env files)
• https://github.com/kaliber5/k5-ember-boilerplate/blob/d2040e764f78eb8abfba6bba203b5f4927b2e92e/blueprints/%40kaliber5/k5-ember-boilerplate/index.js#L130-L131