## Bug description

Trying to look at insights for feature flags no longer works (see screenshot below).

<img width="1329" alt="" src="https://user-images.githubusercontent.com/5864173/100642031-de24cb00-32fd-11eb-88b4-047c4f82124f.png">


Removing the breakdown works but then you can't see the difference between the binary values.

![image](https://user-images.githubusercontent.com/5864173/100642046-e2e97f00-32fd-11eb-8ae5-4238f899c8b8.png)


## Expected behavior

Insights should be shown as before.


## How to reproduce

1. Click on the insights link on any feature flag row.

## Environment

Cloud (Clickhouse).

## Additional context



#### *Thank you* for your bug report – we love squashing them!

ee/clickhouse/queries/test/test_trends.py
with freeze_time("2020-01-03T13:01:01Z"):
            _create_event(
                team=self.team,
                event="sign up",
                distinct_id="blabla",
                properties={"$current_url": "first url", "$browser": "Firefox", "$os": "Mac"},
            )
            _create_event(
                team=self.team,
                event="sign up",
                distinct_id="blabla",
                properties={"$current_url": "first url", "$browser": "Chrome", "$os": "Windows"},
            )
        with freeze_time("2020-01-04T13:01:01Z"):
            _create_event(
                team=self.team,
                event="sign up",
                distinct_id="blabla",
                properties={"$current_url": "second url", "$browser": "Firefox", "$os": "Mac"},
            )
            _create_event(
                team=self.team,
                event="sign up",