wazo-webhookd: No more webhook logs at all after subscription is removed
Given 2 webhook subscriptions A and B
Given one webhook A1 is triggered
Given I remove the webhook subscription A while the webhook A1 is still running
When I trigger a webhook B1
Then I do not see the webhook in `GET /subscription/B/logs`
Expected: I can see B1 in `GET /subscription/B/logs`
It also seems that webhooks are triggered twice.