fixing client instantiation

Author: Aaron Hill

samples/knowledge/qna_maker_samples.py

@@ -57,7 +57,7 @@ def _monitor_operation(client, operation):
                 operation.operation_id))
         return operation
 
-    client = QnAMakerClient(endpoint=QNA_ENDPOINT), credentials=CognitiveServicesCredentials(subscription_key))
+    client = QnAMakerClient(endpoint=QNA_ENDPOINT, credentials=CognitiveServicesCredentials(subscription_key))
 
     # Create a KB
     print("Creating KB...")