Hide uncertainty on CF table load

[mrvisscher]

Fixes bug where CF table shows uncertainty even though "Hide uncertainty columns" is checked.

• fixes uncertainty columns not hidden when opening IC #1415

Checklist

• Keep pull requests small so they can be easily reviewed.
• Update the documentation
  • For in-code documentation, please follow the numpy style guide.
  • For user documentation, please update the wiki in
    ./activity_browser/docs/wiki
• Update tests.
• Link this PR to related issues by using closing keywords.

If you have write access (otherwise a maintainer will do this for you):

• Categorize the PR by setting a good title and adding one of the labels:
  bug, feature, ui, change, documentation, breaking, ci
  as they show up in the changelog.
• Add a milestone to the PR (and related issues, if any) for the intended release.
• Request a review from another developer. - Small and quick, will close myself

[coveralls]

coverage: 53.279% (-0.04%) from 53.315%
when pulling d467710 on mrvisscher:cf-table-hide-uncertainty
into 8f0b620 on LCA-ActivityBrowser:main.