title: Cannot drop 'local' database while replication is active
body: <p>I've rs.remove(secondary) from the primary server, now going back to that secondary i want to delete all the data so i can set it up with a other primary, so i've deleted the /var/lib/mongodb, now going back to check if everything is deleted, i can only find local db with </p>
  
  <pre><code>replset.minvalid
  replset.oplogTruncateAfterPoint
  startup_log
  system.rollback.id
  </code></pre>
  
  <p>so when i db.dropDatabase()
  i get the following </p>
  
  <pre><code>"operationTime" : Timestamp(0, 0),
      "ok" : 0,
      "errmsg" : "Cannot drop 'local' database while replication is active",
      "code" : 20,
      "codeName" : "IllegalOperation",
      "$clusterTime" : {
          "clusterTime" : Timestamp(0, 0),
          "signature" : {
              "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
              "keyId" : NumberLong(0)
  </code></pre>
  
  <p>what is wrong ?</p>