Logrus hook prints error if event has been dropped

When using the logrus hook to send logs to sentry, the following line is printed everytime the hook is triggered but the event is dropped (e.g. by using `BeforeSend`):

```
Failed to fire hook: failed to send to sentry
```

The log is triggered by [this particular error]().
I think this error should not be thrown at all since it's a valid scenario to drop sentry events client-side.