RFR: 116: Changes link in email notification is wrong for GitLab

[Robin Westberg]

Hi all,

Please review this change that implements proper changes links in notifications for GitLab.

Best regards,
Robin

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Commits:
 - ccfdc1ed: Move getChangeUrl into PullRequest to allow a proper implementation for GitLab

Changes: https://git.openjdk.java.net/skara/pull/187/files
 Webrev: https://webrevs.openjdk.java.net/skara/187/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/SKARA-116
  Stats: 69 lines in 8 files changed: 50 ins; 12 del; 7 mod
  Patch: https://git.openjdk.java.net/skara/pull/187.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/187/head:pull/187

PR: https://git.openjdk.java.net/skara/pull/187