CI integration doesn't work correctly on forked repo MR

Summary

In a MR, the CI pipe line displayed correctly with a third party CI tool, such as Teamcity. However, this feature doesn't work with a forked repo's MR.

Steps to reproduce

1. CI integrated to Teamcity
2. Submit a Merge Request from an user's forked repo to main repo's master branch.
3. Pipe line isn't appeared on the MR. a pipeline progress appears correctly with no-forked branch.

What is the current bug behavior?

• A video of error case can be found from here: https://drive.google.com/file/d/1PtRRgyN7jUgCZWbZHuwVYcaKWFHaBn1D/view?usp=sharing

What is the expected correct behavior?

• A correct behaviour with non-forked branch can be found from here: https://drive.google.com/file/d/1gfIQMQ6YhXYIPk1wcriOvceSE7vwu6D-/view?usp=sharing

Relevant logs and/or screenshots

• Correct case:

• Incorrect case with forked repo: