[s3_bucket] access the bucket encryption response gracefully (#59826)

Signed-off-by: Jakob Ackermann <das7pad@outlook.com>

lib/ansible/modules/cloud/amazon/s3_bucket.py

@@ -419,12 +419,14 @@ def put_bucket_versioning(s3_client, bucket_name, required_versioning):
 def get_bucket_encryption(s3_client, bucket_name):
     try:
         result = s3_client.get_bucket_encryption(Bucket=bucket_name)
-        return result.get('ServerSideEncryptionConfiguration').get('Rules')[0].get('ApplyServerSideEncryptionByDefault')
+        return result.get('ServerSideEncryptionConfiguration', {}).get('Rules', [])[0].get('ApplyServerSideEncryptionByDefault')
     except ClientError as e:
         if e.response['Error']['Code'] == 'ServerSideEncryptionConfigurationNotFoundError':
             return None
         else:
             raise e
+    except (IndexError, KeyError):
+        return None
 
 
 @AWSRetry.exponential_backoff(max_delay=120, catch_extra_error_codes=['NoSuchBucket'])