fix: Fix broken insert_event

Was broken in previous commit, supposed to fix aw-server-rust
compatibility 6521df6

Author: johan-bjareholt

aw_client/client.py

@@ -162,7 +162,7 @@ def send_events(self, bucket_id: str, events: List[Event]):
     def insert_event(self, bucket_id: str, event: Event) -> Event:
         endpoint = "buckets/{}/events".format(bucket_id)
         data = [event.to_json_dict()]
-        return Event(**self._post(endpoint, data).json()[0])
+        return Event(**self._post(endpoint, data).json())
 
     def insert_events(self, bucket_id: str, events: List[Event]) -> None:
         endpoint = "buckets/{}/events".format(bucket_id)