When configuration has 2 or more defined repositories on GitHub (or even Git) and build is triggered via GitHub webhook, all repositories are checked out on pull request number.

Steps to reproduce:
1. Create new configuration
2. Create GitHub Repository abc, without pull requests, on specified branch (e.g. main)
3. Create GitHub repository xyz, with Pull request setting Specified Pull Requests, Type Merge, Ids equal to ${vars.getValue("pr_number")}
4. Create GitHub Webhook with variable pr_number = ${groovy: delivery.pull_request.number }
5. On repository xyz create Pull Request and send webhook to QuickBuild

Expected result:
- repository abc is checked out on specified branch,as it's not contains

Actual result:
- repository abc cannot be cloned, error: 'fatal: couldn't find remote ref refs/pull/<pull request number>/merge'

Workaround:
- fill in Commit or tag to build with HEAD (or valid tag or commit sha)