[bugfix] Fix default datefmt for the perflog handlers

[vkarak]

Closes #3643.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.70%. Comparing base (2fa6300) to head (60412b7).
⚠️ Report is 77 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3644      +/-   ##
===========================================
+ Coverage    91.26%   91.70%   +0.44%     
===========================================
  Files           62       62              
  Lines        13591    13713     +122     
===========================================
+ Hits         12404    12576     +172     
+ Misses        1187     1137      -50     

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