Fix coverage calculation with jacoco

[kwin]

This closes #773

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (develop@14fb37e). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             develop     #774   +/-   ##
==========================================
  Coverage           ?   29.46%           
  Complexity         ?      479           
==========================================
  Files              ?      155           
  Lines              ?     3974           
  Branches           ?      545           
==========================================
  Hits               ?     1171           
  Misses             ?     2649           
  Partials           ?      154           

Flag	Coverage Δ
unittests	29.46% <0.00%> (?)

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