Update articles/iot-operations/manage-mqtt-broker/howto-configure-authentication.md

Co-authored-by: John Lian <[email protected]>

Author: gordonwang0

articles/iot-operations/manage-mqtt-broker/howto-configure-authentication.md

@@ -363,7 +363,7 @@ BinaryData
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-Once the trusted CA certificate is imported, enable X.509 client authentication by adding it as one of the authentication methods in a *BrokerAuthentication* resource linked to a TLS-enabled listener. 
+Once the trusted CA certificate is imported, enable X.509 client authentication by adding it as one of the authentication methods in a *BrokerAuthentication* resource linked to a TLS-enabled listener port. 
 
 ### Certificate attributes for authorization