title: Csvhelper Ingore is removing only header column name but no the actual data
body: <p>I loaded a csv file in my database with a DbId column not in the file.</p>
  
  <p>I want to export it back to the original format.</p>
  
  <p>My csvhelper mapping is in <code>MyCsvClass</code> with   <code>Map(m =&gt; m.DbId).Ignore();</code></p>
  
  <p>Header is fine, but output data is still showing values of DbId column:
  <a href="https://dotnetfiddle.net/XP2Vvq" rel="nofollow noreferrer">https://dotnetfiddle.net/XP2Vvq</a></p>
  
  <pre><code>using CsvHelper.Configuration;
  using System;
  using System.IO;
  
  namespace Test
  {
      class Program
      {
          static void Main(string[] args)
          {
              var record = new { DbId = 1, Data1 = "aaa", Data2 = "bbb" };
  
              using (var sw = new StreamWriter(@"c:/temp/testt.csv"))
              {
                  using (var csvWriter = new CsvHelper.CsvWriter(sw))
                  {
                      csvWriter.Configuration.RegisterClassMap&lt;MyCsvClassMap&gt;();
                      csvWriter.WriteHeader&lt;MyCsvClass&gt;();
                      csvWriter.NextRecord();
                      csvWriter.WriteRecord(record);
                  }
              }
          }
      }
  
      public class MyCsvClassMap : ClassMap&lt;MyCsvClass&gt;
      {
          public MyCsvClassMap()
          {
              AutoMap();
              Map(m =&gt; m.DbId).Ignore();
          }
      }
  
      public class MyCsvClass
      {
          public int DbId { get; set; }
          public string Data1 { get; set; }
          public string Data2 { get; set; }      
      }   
  }
  </code></pre>
  
  <p>Output is </p>
  
  <pre><code>Data1, Data2
  1, "aaa", "bbb"
  </code></pre>
  
  <p>when I expect</p>
  
  <pre><code>Data1, Data2
  "aaa", "bbb"
  </code></pre>