🐛 Fixed comp plans for members w/ active subscriptions
🐛 Fixed comp plans for members w/ active subscriptions

refs https://github.com/TryGhost/Team/issues/475

The subscription object here is a database model rather than an
ISubscription from the stripe library, and we need to 1) use the `get`
method to read attributes and 2) read the `subscription_id` attribute,
as the `id` is our internal one.

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