fix collection prefix extraction

4 jobs for master in 8 minutes and 12 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed test-chart #114985
mbr

00:00:11

passed test-sbt #114986

00:03:26

 
  Build
passed assembly-sbt #114987

00:02:57

 
  Publish
passed build-latest-image #114988

00:01:48