[che-server] ci/prow/v19-gitlab-with-oauth-setup-flow PR check failed

[svor]

Is your task related to a problem? Please describe

PR check ci/prow/v19-gitlab-with-oauth-setup-flow failed in che-server repo, for example in this PR: eclipse-che/che-server#962

Describe the solution you'd like

Investigate why the test is failing and resolve the issue.

[artaleks9]

@vinokurig @olexii4 @svor
It seems, in the Che-next there is a bug related to failure run workspace from factory Url when OAuth is configured. This was reproduced on both gitlab-server and GitLab.com providers, see the video.
This is also a reason of fail PR-checks eclipse-che/che-server#962 and eclipse-che/che-server#951.

gitlab-server OAuth configured:

gitlab-server-oauth.mp4

GitLab.com OAuth configured:

gitlab-com-oauth.mp4

[artaleks9]

Validating the OAuth flow using a pull request (PR) works correctly when using the fix from the pull request eclipse-che/che-server#964