FYI: Fix GitLab source_project_id api call

[Robin Westberg]

Hi all,

Please review this small change that fixes a GitLab specific API call.

Best regards,
Robin

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Commit messages:
 - Fix source_project_id api call

Changes: https://git.openjdk.java.net/skara/pull/573/files
 Webrev: https://webrevs.openjdk.java.net/skara/573/webrev.00
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/skara/pull/573.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/573/head:pull/573

PR: https://git.openjdk.java.net/skara/pull/573