RFR: 8332008: Enable issuestitle check

[Zhao Song]

As requested in [SKARA-2170](https://bugs.openjdk.org/browse/SKARA-2170) and [SKARA-2248](https://bugs.openjdk.org/browse/SKARA-2248), now Skara bot is able to warn on trailing periods or leading lowercase letter in issue titles.
I am going to update the jcheck configuration to configure issuestitle check as a warning. Given that it's just a warning, it wouldn't block integration.

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Commit messages:
 - JDK-8332008

Changes: https://git.openjdk.org/jdk/pull/19161/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19161&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8332008
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/19161.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19161/head:pull/19161

PR: https://git.openjdk.org/jdk/pull/19161