don't write header if no respective value present

Signed-off-by: Sebastian Schüpbach <sebastian.schuepbach@unibas.ch>
3 jobs for master in 3 minutes and 59 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
passed test #62721
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00:01:36

passed test-chart #62722
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00:00:14

 
  Publish
passed build-latest-image #62723
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00:02:22