## Bug description

This is what a default feature flag looks like:
<img width="577" alt="empty feature flag" src="https://user-images.githubusercontent.com/4550621/113333154-63f36a00-9322-11eb-8fb0-71b0cd865181.png">
It has no rollout percentage specified, nor filters, so it says "Rolling out to 100% of users". However I've experienced that in fact in this situation the flag is rolled out to *nobody*.

CC @paolodamico 

## Expected behavior

Flag should work the way it says.

## How to reproduce

1. Create a feature flag and leave it as is, supposedly completely rolled out.
2. Try to use it.
3. Discover that the flag is not rolled out.

## Environment

- [x] PostHog Cloud
- [x] self-hosted PostHog, version/commit: master (8f4ae2b)

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

posthog/api/test/test_decide.py
created_by=self.user,
        )
        with self.assertNumQueries(5):
            response = self._post_decide().json()
        self.assertEqual(response["featureFlags"][0], "beta-feature")
        with self.assertNumQueries(5):
            response = self._post_decide({"token": self.team.api_token, "distinct_id": "another_id"}).json()
        self.assertEqual(len(response["featureFlags"]), 0)
    def test_feature_flags_with_personal_api_key(self):
        key = PersonalAPIKey(label="X", user=self.user)
        key.save()
        Person.objects.create(team=self.team, distinct_ids=["example_id"])
        FeatureFlag.objects.create(
            team=self.team, rollout_percentage=100, name="Test", key="test", created_by=self.user,
        )
        response = self._post_decide(
            {"distinct_id": "example_id", "api_key": key.value, "project_id": self.team.id}
        ).json()
        self.assertEqual(len(response["featureFlags"]), 1)
    def test_personal_api_key_without_project_id(self):
        key = PersonalAPIKey(label="X", user=self.user)
        key.save()
        Person.objects.create(team=self.team, distinct_ids=["example_id"])
        response = self._post_decide({"distinct_id": "example_id", "api_key": key.value})
        self.assertEqual(response.status_code, 401)
        self.assertEqual(
            response.json()["message"],
            "Project API key invalid. You can find your project API key in PostHog project settings.",
        )