Fix import.

Author: vmagelo

articles/event-hubs/event-hubs-python-get-started-send.md

@@ -65,7 +65,7 @@ In this section, create a Python script to send events to the event hub that you
 
     from azure.eventhub import EventData
     from azure.eventhub.aio import EventHubProducerClient
-    from azure.identity import DefaultAzureCredential
+    from azure.identity.aio import DefaultAzureCredential
 
     EVENT_HUB_FULLY_QUALIFIED_NAMESPACE = "EVENT_HUB_FULLY_QUALIFIED_NAMESPACE"
     EVENT_HUB_NAME = "EVENT_HUB_NAME"