RFR: Revert "819: Backports created by Robo Duke inherit all labels of original"

[Robin Westberg]

This reverts commit 9a98403ebfa74a8e0ab7d520b77f9ac6a3a730bc.

Preparation for a different method of avoiding label propagation.

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Commit messages:
 - Revert "819: Backports created by Robo Duke inherit all labels of original"

Changes: https://git.openjdk.java.net/skara/pull/964/files
 Webrev: https://webrevs.openjdk.java.net/?repo=skara&pr=964&range=00
  Stats: 242 lines in 7 files changed: 203 ins; 31 del; 8 mod
  Patch: https://git.openjdk.java.net/skara/pull/964.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/964/head:pull/964

PR: https://git.openjdk.java.net/skara/pull/964