RFR: 1618: CSR bot failed to update PR when CSR was approved

[Erik Joelsson]

This patch fixes a mistake in the CSRBotFactory. The intention was to create one CSRIssueBot for each unique IssueProject, but we currently get one per repository instead. This is because JiraProject doesn't implement hashcode, so we can't trust a HashSet to sort out uniqueness. I'm changing this to a HashMap and using the configuration string as key instead.

For details on how this was causing the reported problem, see comments in the bug.

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Commit messages:
 - SKARA-1618

Changes: https://git.openjdk.org/skara/pull/1391/files
 Webrev: https://webrevs.openjdk.org/?repo=skara&pr=1391&range=00
  Issue: https://bugs.openjdk.org/browse/SKARA-1618
  Stats: 9 lines in 1 file changed: 4 ins; 1 del; 4 mod
  Patch: https://git.openjdk.org/skara/pull/1391.diff
  Fetch: git fetch https://git.openjdk.org/skara pull/1391/head:pull/1391

PR: https://git.openjdk.org/skara/pull/1391