Remove already canceled subscriptions (hacktoolkit#428)

Handle to remove already `canceled` Stripe subscriptions that happened
may be due to `Stripe Payment Failure` or other reasons.

lib/stripe_lib/models.py

@@ -593,9 +593,15 @@ def cancel(self):
         subscription = self.retrieve()
 
         if subscription:
-            args = (subscription.get('id'),)
-            obj = safe_stripe_call(self.STRIPE_API_CLASS.delete, *args)
-            was_deleted = obj is not None and obj.get('status') == 'canceled'
+            # Subscription `status` set to `canceled` already
+            # may be due to `Stripe Payment Failure` or other reasons
+            was_deleted = subscription.get('status') == 'canceled'
+
+            # Subscription is `active` and should be deleted
+            if not was_deleted:
+                args = (subscription.get('id'),)
+                obj = safe_stripe_call(self.STRIPE_API_CLASS.delete, *args)
+                was_deleted = obj is not None and obj.get('status') == 'canceled'
         else:
             was_deleted = False