making export to csv export everything (issue #2947)
Revert "making export to csv export everything (issue #2947)"

This reverts commit bf2801946582ec6621fe726448f5fd3d1472f818.
fix challenge export to csv to export all tasks (issue #2947)
Merge pull request #4028 from Verabird/challengecvsalt

Make export to csv button on challenges export all tasks (issue #2947)