title: RethinkDB OrderBy ignored
body: <p>I have working RethinkDB with C# application querying for data - I have created index for one of fields but got different results when running from Web UI or C# application (using driver)</p>
  
  <p>here is my query from Web UI:</p>
  
  <pre><code>r.db('db_data').table('table_data').orderBy({index:r.desc('my_index')}).limit(1)
  </code></pre>
  
  <p>and here is my C# code:</p>
  
  <pre><code>RethinkDB.R.
     Db(mSelectedDB).
     Table(mSelectedTable).
     OrderBy(RethinkDB.R.Desc("my_index")).OptArg("index", "my_index").
     Limit(1)
     Run(conn);
  </code></pre>
  
  <p>when I run from Web I correctly get <strong>last result</strong>, but form C# app I <strong>get first</strong> - so my OrderBy doesn't work, what am I doing wrong here? ATM only working solution in C# is to use Nth(-1) instead of Limit(1) + R.Desc but that is muuuuch slower so I'd prefer to avoid it.</p>
  
  <p>environment: VS 2015, RethinkDb.Driver.2.3.15</p>