RFR: 2408: Require at least one component/area label before a PR can be integrated

[Zhao Song]

This patch is trying to improve the bot by ensuring that if the repo has the label configuration, then any pull request in this repo should only be marked as "rfr" when at least one component is associated with the pr.

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Commit messages:
 - update
 - SKARA-2048

Changes: https://git.openjdk.org/skara/pull/1727/files
  Webrev: https://webrevs.openjdk.org/?repo=skara&pr=1727&range=00
  Issue: https://bugs.openjdk.org/browse/SKARA-2408
  Stats: 14 lines in 2 files changed: 11 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/skara/pull/1727.diff
  Fetch: git fetch https://git.openjdk.org/skara.git pull/1727/head:pull/1727

PR: https://git.openjdk.org/skara/pull/1727