pirania: preserve config on upgrade.

[germanferrero]

Also, remove non used config options.

[codecov-commenter]

Codecov Report

Merging #921 (c75c8dd) into master (eebacf8) will not change coverage.
The diff coverage is n/a.

❗ Current head c75c8dd differs from pull request most recent head 39fe2de. Consider uploading reports for the commit 39fe2de to get more accurate results

@@           Coverage Diff           @@
##           master     #921   +/-   ##
=======================================
  Coverage   77.00%   77.00%           
=======================================
  Files          48       48           
  Lines        4057     4057           
=======================================
  Hits         3124     3124           
  Misses        933      933           

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