RFR: 1729: CSR bot should not remove CSR label if one of the CSR issues is withdrawn [v3]

[Zhao Song]

> While testing [SKARA-1714](https://bugs.openjdk.org/browse/SKARA-1714), I discovered a bug in the PullRequestWorkItem of the CSR bot. 
> 
> Currently, the CSR bot would remove CSR label if all the CSR issues of the pr is closed(whether approved or withdrawn). However, if the CSR label is added via using '/csr needed' command and the pr contains withdrawn CSR issues, the CSR should not remove the CSR label.

Zhao Song has updated the pull request incrementally with one additional commit since the last revision:

  change the logic about the method isCSRNeeded

-------------

Changes:
  - all: https://git.openjdk.org/skara/pull/1451/files
  - new: https://git.openjdk.org/skara/pull/1451/files/4b9f58f0..5aad0337

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=skara&pr=1451&range=02
 - incr: https://webrevs.openjdk.org/?repo=skara&pr=1451&range=01-02

  Stats: 8 lines in 1 file changed: 0 ins; 0 del; 8 mod
  Patch: https://git.openjdk.org/skara/pull/1451.diff
  Fetch: git fetch https://git.openjdk.org/skara pull/1451/head:pull/1451

PR: https://git.openjdk.org/skara/pull/1451