Deserialize nullable with null value

When the type being deserialized has an string value it return de default value of the underlying type instead of null

Author: Dini001

FileContextCore/Serializer/SerializerHelper.cs

@@ -13,13 +13,13 @@ static class SerializerHelper
     {
         public static object Deserialize(this string input, Type type)
         {
-	        type = Nullable.GetUnderlyingType(type) ?? type;
-
             if (string.IsNullOrEmpty(input))
             {
                 return type.GetDefaultValue();
             }
 
+	    type = Nullable.GetUnderlyingType(type) ?? type;
+
             if (type == typeof(DateTimeOffset))
             {
                 return DateTimeOffset.Parse(input, CultureInfo.InvariantCulture);