[frontend] fix channels filter in definition

[guillaumejparis]

closes #868

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 26.04%. Comparing base (624597b) to head (ca41e87).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1049 +/- ## ============================================ + Coverage 25.74% 26.04% +0.30% - Complexity 1001 1005 +4 ============================================ Files 448 448 Lines 10582 10582 Branches 514 514 ============================================ + Hits 2724 2756 +32 + Misses 7795 7763 -32 Partials 63 63 ```

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