`get_feature_flag_result` returns `None` instead of `FeatureFlagResult` when payload is `""`

[mzgajner]

Reproduction:

• Configure a feature flag with multiple variants
• Enter string payloads for variants and make one of the payloads an empty string (e.g. "ONE", "TWO" and "").
• Configure a python posthog client and call get_feature_flag_result for your flag
• If the result is one of the first two variants, the function normally returns a FeatureFlagResult with payload set to "ONE" or "TWO"
• If the result is the third variant, the function instead returns None

This looks like a bug to me, I would expect to get back a FeatureFlagResult with the payload set to "" instead.

[dmarticus]

hi @mzgajner , thanks for reporting! this should be fixed in v6.3.3 of posthog-python