revert metadata blocking setting

es_curls

//create an index
curl -XPUT 'http://127.0.0.1:9200/test1'
{
  "settings": {
    "index": {
      "number_of_shards": 1,
      "number_of_replicas": 0
    }
  }
}

//close the index 
curl -XPOST 'http://localhost:9200/test1/_close'
{
}

//disable metadata changes
curl -XPUT 'http://127.0.0.1:9200/test1/_settings'
{
   "index": {
      "blocks":{
        "metadata":true
      }
    }
}

//how to revert it back???