Update batch-docker-container-workloads.md

Author: wiboris

articles/batch/batch-docker-container-workloads.md

@@ -340,7 +340,7 @@ CloudPool pool = batchClient.PoolOperations.CreatePool(
 ### Managed identity support for ACR
 
 When you access containers stored in [Azure Container Registry](https://azure.microsoft.com/services/container-registry),
-either a username/password or a managed identity can be used to authenticate with the service. To use a managed identity,
+a managed identity can be used to authenticate with the service. To use a managed identity,
 first ensure that the identity has been [assigned to the pool](managed-identity-pools.md) and that the identity has the
 `AcrPull` role assigned for the container registry you wish to access. Then, instruct Batch with which identity to use
 when authenticating with ACR.