Before submitting your PR, please review the following checklist:

• CHOOSE CORRECT BRANCH: if filing a bugfix/enhancement
  against certain release version, choose 0.9, 0.10 or 0.11 branch,
  for dev-edition use master branch
• CONSIDER adding a unit test if your PR resolves an issue
• LIST ISSUES this PR resolves
• MAKE SURE this PR doesn't break existing tests
• KEEP PR small so it could be easily reviewed.
• AVOID making unnecessary stylistic changes in unrelated code
• ACCOMPANY each new failregex for filter X with sample log lines
  within fail2ban/tests/files/logs/X file