title: mongodb replicaset host name change error
body: <p>I have a mongodb replicaset on ubuntu.. In replica set, hosts are defined as localhost. You can see ;</p>
  
  <pre><code>{
      "_id" : "myrep",
      "version" : 4,
      "members" : [
              {
                      "_id" : 0,
                      "host" : "localhost:27017"
              },
              {
                      "_id" : 2,
                      "host" : "localhost:27018"
              },
              {
                      "_id" : 1,
                      "host" : "localhost:27019",
                      "priority" : 0
              }
      ]
  </code></pre>
  
  <p>}</p>
  
  <p>I want to change host adresses with real ip of server. But when i run rs.reconfig, I get error :</p>
  
  <pre><code>{
      "assertion" : "hosts cannot switch between localhost and hostname",
      "assertionCode" : 13645,
      "errmsg" : "db assertion failure",
      "ok" : 0
  </code></pre>
  
  <p>}</p>
  
  <p>How can i solve it ?
  Thank you.</p>