Update connect-aws.md

Author: guywi-ms

articles/sentinel/connect-aws.md

@@ -207,7 +207,7 @@ Setting up this connector has two steps:
 
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-## Send formatted CloudWatch events to S3 using a lambda function
+## Send formatted CloudWatch events to S3 using a lambda function (optional)
 
 If your CloudWatch logs aren't in the format accepted by Microsoft Sentinel - .csv file in a GZIP format without a header - use a lambda function ([view the source code](https://github.com/Azure/Azure-Sentinel/blob/master/DataConnectors/AWS-S3/CloudWatchLambdaFunction.py)) within AWS to send CloudWatch events to an S3 bucket in the accepted format.