[Rev 01] RFR: Handle links already deleted

[Robin Westberg]

> Hi all,
> 
> Please review this small change that gracefully handles removing Jira links that have already been deleted.
> 
> Best regards,
> Robin

The pull request has been updated with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase.

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

Added commits:
 - eb30e832: Adapt to latest upstream changes
 - df597cb0: Merge remote-tracking branch 'upstream/master' into jira_remove_unknown_link
 - bc37f619: git-jcheck: add pre-push support
 - b090b57c: vcs: add Hash::zero
 - 0e9e8412: Make the rest request error transform optional

Changes:
  - all: https://git.openjdk.java.net/skara/pull/467/files
  - new: https://git.openjdk.java.net/skara/pull/467/files/2d237d75..eb30e832

Webrevs:
 - full: https://webrevs.openjdk.java.net/skara/467/webrev.01
 - incr: https://webrevs.openjdk.java.net/skara/467/webrev.00-01

  Stats: 147 lines in 23 files changed: 58 ins; 17 del; 72 mod
  Patch: https://git.openjdk.java.net/skara/pull/467.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/467/head:pull/467

PR: https://git.openjdk.java.net/skara/pull/467