Error message about required pipeline file .yml extension mentions .gitlab.yml file name which could not be accurate

Summary

I'm using custom path to pipeline file which is continuous-integration/gitlab/pipeline instead of default .gitlab-ci.yml.

Gitlab instance is upgraded to version 12.6.4 and then I've got error that pipepline file now have to have .yml extension. That's ok, I can rename this file.

But error message still mentions .gitlab-ci.yml which is not accurate.

Steps to reproduce

Install some older version of gitlab. Create new project and set custom path to your pipeline file without any extension named differently then default gitlab-ci.yml. Then upgrade gitlab to version 12.6.4. Push new commit and you will get error when running pipeline.

What is the current bug behavior?

Found errors in your .gitlab-ci.yml:
Included file `continuous-integration/gitlab/pipeline` does not have YAML extension!
You can also test your .gitlab-ci.yml in CI Lint 

What is the expected correct behavior?

Should it be something more generic? Like

Found errors in your pipeline file:
Included file `continuous-integration/gitlab/pipeline` does not have YAML extension (.yml)!
You can also test your pipeline file in CI Lint