RFR: 2278: Issuestitle Check shouldn't treat special character as leading lowercase letter

[Zhao Song]

Currently, in IssuesTitleCheck::hasLeadingLowercaseLetter, the method checks if the leading character is uppercase, if so, it returns false. Otherwise, it will treat the character as lowercase. This is wrong because it treats special characters as lowercase letters. The solution is to make the method to check if the leading character is a lowercase letter.

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Commit messages:
 - SKARA-2278

Changes: https://git.openjdk.org/skara/pull/1656/files
  Webrev: https://webrevs.openjdk.org/?repo=skara&pr=1656&range=00
  Issue: https://bugs.openjdk.org/browse/SKARA-2278
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/skara/pull/1656.diff
  Fetch: git fetch https://git.openjdk.org/skara.git pull/1656/head:pull/1656

PR: https://git.openjdk.org/skara/pull/1656