Fix append_logic_xor test

[xevisalle]

Fixes a problem in the tests related to append_logic_xor. It computed an xor operation without taking into account the modulus applied to all operations. Basically:

((a ^ b) & bit_mask) % mod != (((a ^ b) % mod) & bit_mask) % mod

[codecov]

Codecov Report

Merging #780 (1ad528f) into master (8f9cf5a) will increase coverage by 1.02%.
The diff coverage is 100.00%.

❗ Current head 1ad528f differs from pull request most recent head f7c2fa9. Consider uploading reports for the commit f7c2fa9 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #780      +/-   ##
==========================================
+ Coverage   84.02%   85.05%   +1.02%     
==========================================
  Files          57       57              
  Lines        4094     4047      -47     
==========================================
+ Hits         3440     3442       +2     
+ Misses        654      605      -49     

Files	Coverage Δ
tests/logic.rs	98.21% <100.00%> (+30.28%)	⬆️

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[moCello]

LGTM