Fix example error Anca pointed out

Author: jlian

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

@@ -242,6 +242,7 @@ resource myBrokerAuthentication 'Microsoft.IoTOperations/instances/brokers/authe
       {
         method: 'X509'
         x509Settings: {
+          trustedClientCaCert: 'client-ca'
           authorizationAttributes: {
             root: {
               attributes: {
@@ -305,8 +306,8 @@ spec:
         - my-audience
     - method: X509
       x509Settings:
+        trustedClientCaCert: client-ca
         authorizationAttributes:
-          trustedClientCaCert: client-ca
           root:
             attributes:
               organization: contoso