Update blob.json (#10061)

specification/storage/resource-manager/Microsoft.Storage/stable/2019-06-01/blob.json

@@ -607,7 +607,7 @@
             "$ref": "./examples/BlobContainersDeleteImmutabilityPolicy.json"
           }
         },
-        "description": "Aborts an unlocked immutability policy. The response of delete has immutabilityPeriodSinceCreationInDays set to 0. ETag in If-Match is required for this operation. Deleting a locked immutability policy is not allowed, only way is to delete the container after deleting all blobs inside the container.",
+        "description": "Aborts an unlocked immutability policy. The response of delete has immutabilityPeriodSinceCreationInDays set to 0. ETag in If-Match is required for this operation. Deleting a locked immutability policy is not allowed, the only way is to delete the container after deleting all expired blobs inside the policy locked container.",
         "parameters": [
           {
             "$ref": "./storage.json#/parameters/ResourceGroupName"