RFR: 690: Merge commit message is not Merge jdk, but: Merge jdk [v2]

[Erik Helin]

> Hi all,
> 
> please review this patch that makes it more clear what the expected and current commit messages are when showing the
> error for `MergeMessageCheck`.
> Thanks,
> Erik

Erik Helin has refreshed the contents of this pull request, and previous commits have been removed. The incremental
views will show differences compared to the previous content of the PR. The pull request contains one new commit since
the last revision:

  690

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

Changes:
  - all: https://git.openjdk.java.net/skara/pull/831/files
  - new: https://git.openjdk.java.net/skara/pull/831/files/fc746103..8a9fb6ae

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=skara&pr=831&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=skara&pr=831&range=00-01

  Stats: 4 lines in 1 file changed: 0 ins; 3 del; 1 mod
  Patch: https://git.openjdk.java.net/skara/pull/831.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/831/head:pull/831

PR: https://git.openjdk.java.net/skara/pull/831