[BUG] Column index out of range

**Describe the bug**
From the logs of rpgf4-production:
```
RangeError: Column index out of range |  
-- | --
  |   | at async /usr/src/app/node_modules/@nestjs/core/router/router-proxy.js:9:17 |  
  |   | at async /usr/src/app/node_modules/@nestjs/core/router/router-execution-context.js:46:28 |  
  |   | at async FlowController.finishCollections (/usr/src/app/dist/src/flow/flow.controller.js:173:9) |  
  |   | at async FlowService.finishCollection (/usr/src/app/dist/src/flow/flow.service.js:1074:9) |  
  |   | at async FlowService.saveResultsFromVotes (/usr/src/app/dist/src/flow/flow.service.js:474:29) |  
  |   | at FlowService.getRankingFromVotes (/usr/src/app/dist/src/flow/flow.service.js:550:86) |  
  |   | at getRankingForSetOfDampingFactors (/usr/src/app/dist/src/utils/mathematical-logic/index.js:68:62) |  
  |   | at calculateCollectionRanking (/usr/src/app/dist/src/utils/mathematical-logic/index.js:122:30) |  
  |   | at Matrix.getColumn (/usr/src/app/node_modules/ml-matrix/matrix.js:1683:5) |  
  |   | at checkColumnIndex (/usr/src/app/node_modules/ml-matrix/matrix.js:952:11)
```

**To Reproduce**
- get credentials for `logs.generalmagic.io` from GM devops
- visit the logs at https://logs.generalmagic.io/d/dc43581e-888c-4095-9c7b-6f8d60cf61ce/rpgf4-pairwise-production?orgId=1