Closes #2751 filter.d/sendmail-*.local configparser recursion issue

[yolabingo]

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

[codecov-commenter]

Codecov Report

Merging #2752 into master will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2752      +/-   ##
==========================================
+ Coverage   95.84%   95.86%   +0.01%     
==========================================
  Files          78       78              
  Lines       15750    15750              
  Branches     2560     2560              
==========================================
+ Hits        15096    15098       +2     
+ Misses        350      348       -2     
  Partials      304      304              

Impacted Files	Coverage Δ
fail2ban/server/utils.py	90.07% <0.00%> (+0.39%)	⬆️
fail2ban/server/filterpyinotify.py	94.31% <0.00%> (+0.47%)	⬆️

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[coveralls]

Coverage remained the same at 98.038% when pulling 3c03514 on yolabingo:master into 6cff2bb on fail2ban:master.

[coveralls]

Coverage remained the same at 98.038% when pulling 3c03514 on yolabingo:master into 6cff2bb on fail2ban:master.

[sebres]

See #2751 (comment)