fix: write subconfig fields only if driver has value for this fields

[Insei]

No description provided.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 86.36364% with 3 lines in your changes missing coverage. Please review.

Project coverage is 91.68%. Comparing base (0a5bcef) to head (f46a1b1).

Files with missing lines	Patch %	Lines
parser.go	86.36%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #12      +/-   ##
==========================================
+ Coverage   91.50%   91.68%   +0.18%     
==========================================
  Files          10       10              
  Lines         506      517      +11     
==========================================
+ Hits          463      474      +11     
  Misses         36       36              
  Partials        7        7              

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