Pipelines endpoint returns invalid URLs for self and steps fields

Issue Summary

• Responses from the Pipelines endpoint returns an invalid URL for both self and steps fields which can't be accessed with regular <username:apppassword> authorization header;

• "links": {
          "self": {
            "href": "https://bitbucket-pipelines.prod.public.atl-paas.net//rest/1.0/accounts/{workspace_uuid}/repositories/{repo_uuid}/pipelines/{build_uuid}"
          },
          "steps": {
            "href": "https://bitbucket-pipelines.prod.public.atl-paas.net//rest/1.0/accounts/{workspace_uuid}/repositories/{repo_uuid}/pipelines/{build_uuid}/steps"
          }
        } 

Steps to Reproduce

1. Make an API call to the Pipelines endpoint for any repository
2. In the results, you will see a Links object with two URLs: self and steps;
3. Try to make a GET request to that URL;

Expected Results

Results should use the actual api.bitbucket.org domain, making it possible to fetch results from these URLs;

Actual Results

Fetching the build and the steps from these URLs fail with authorization error:

{
  "error": {
    "message": "Unauthorized",
    "detail": "No authorization provider header specified.",
    "data": {
      "key": "rest-service.rest-service.unauthorized",
      "arguments": {}
    }
  }
} 

Workaround

Directly fetch the build and steps from our API sub-domain;

/2.0/repositories/{workspace}/{repo_slug}/pipelines/{pipeline_uuid} 

and

/2.0/repositories/{workspace}/{repo_slug}/pipelines/{pipeline_uuid}/steps/