title: JsonConvert PopulateObject when updating object doesnt populate null value to nullable integer
body: <p>I am trying to update an user object</p>
  <p>Here is my model:</p>
  <pre><code>public class User:BaseModel
  {
      [Display(Name=&quot;E-Posta&quot;),Required(ErrorMessage =&quot;Kullanıcı adı (Email) Zorunludur&quot;)]
      [JsonProperty(NullValueHandling = NullValueHandling.Ignore, PropertyName = &quot;Email&quot;)]
      [DataType(DataType.EmailAddress)]
      [EmailAddress(ErrorMessage = &quot;Hatalı E-Posta&quot;)]
      public string Email { get; set; }
      [Display(Name=&quot;Firma Ünvanı&quot;)]
      [JsonProperty(NullValueHandling = NullValueHandling.Ignore, PropertyName = &quot;FirmTitle&quot;)]
      public string FirmTitle { get; set; }
      [Display(Name = &quot;Vergi Numarası&quot;)]
      [StringLength(11, ErrorMessage = &quot;Vergi Kimlik Numarası 10 veya 11 karakter olmalıdır&quot;, MinimumLength = 10)]
      [JsonProperty(PropertyName = &quot;VKN&quot;)]
      public string VKN { get; set; }
      [Display(Name=&quot;Alıcılar E-Posta&quot;)]
      [JsonProperty(NullValueHandling = NullValueHandling.Ignore, PropertyName = &quot;DocumentReceivers&quot;)]
      public string DocumentReceivers { get; set; }
      [Display(Name=&quot;Sap Lojistik Id&quot;)]
      [JsonProperty(NullValueHandling = NullValueHandling.Ignore, PropertyName = &quot;SAPLogisticId&quot;)]
      public int? SAPLogisticId { get; set; }
      [Display(Name=&quot;Parola&quot;), Required(ErrorMessage = &quot;Parola Zorunludur&quot;)]
      [JsonProperty(NullValueHandling = NullValueHandling.Ignore, PropertyName = &quot;Password&quot;)]
      [DataType(DataType.Password)]
      public string Password { get; set; }
      [Display(Name=&quot;Rol&quot;),Required(ErrorMessage =&quot;Bu alan Gereklidir&quot;)]
      [JsonProperty(NullValueHandling = NullValueHandling.Ignore, PropertyName = &quot;Role&quot;)]
      public string Role { get; set; }
      [Display(Name=&quot;Oluşturulma Tarihi&quot;)]
      [JsonProperty(NullValueHandling = NullValueHandling.Ignore, PropertyName = &quot;CreatedDate&quot;)]
      public DateTime CreatedDate { get; set; }
  }
  </code></pre>
  <p>I have one nullable <code>int?</code> named <code>SAPLogisticId</code> which I am trying to set null value</p>
  <pre><code>var values = &quot;{\&quot;SAPLogisticId\&quot;:null}&quot;;
  int key=4;
  var user = userManager.Get(key);
  JsonConvert.PopulateObject(values, user,new JsonSerializerSettings()
  {
     NullValueHandling = NullValueHandling.Ignore,
     ContractResolver = new CamelCasePropertyNamesContractResolver() { NamingStrategy = null }
  });
  </code></pre>
  <p>But it is not setting the value of <code>SAPLogisticId</code> it does nothing</p>
  <p><strong>Other properties does WORK</strong></p>