Fix null reference error when deserializing bytes

If the JSON contained empty object "{}" for a byte[] property, the `JsonReader` ended up trying to read the object content despite the fact that the content didn't exist. This caused a null reference exception.

The fix ensures the value exists before trying to read it. If the value doesn't exist, the execution ends up in "Unexpected token" exception with way more informative error message.

Src/Newtonsoft.Json.Tests/JsonTextReaderTests/ExceptionHandlingTests.cs

@@ -384,6 +384,14 @@ namespace Newtonsoft.Json.Tests.JsonTextReaderTests
             ExceptionAssert.Throws<JsonReaderException>(() => { reader.ReadAsBytes(); }, "Unexpected end when reading JSON. Path '', line 1, position 1.");
         }
 
+        [Test]
+        public void ReadBytesEmptyWrappedObject()
+        {
+            JsonTextReader reader = new JsonTextReader(new StringReader(@"{}"));
+
+            ExceptionAssert.Throws<JsonReaderException>(() => { reader.ReadAsBytes(); }, "Error reading bytes. Unexpected token: StartObject. Path '', line 1, position 2." );
+        }
+
         [Test]
         public void ReadIntegerWithError()
         {

Src/Newtonsoft.Json/JsonReader.cs

@@ -904,7 +904,7 @@ namespace Newtonsoft.Json
         internal void ReadIntoWrappedTypeObject()
         {
             ReaderReadAndAssert();
-            if (Value.ToString() == JsonTypeReflector.TypePropertyName)
+            if (Value != null && Value.ToString() == JsonTypeReflector.TypePropertyName)
             {
                 ReaderReadAndAssert();
                 if (Value != null && Value.ToString().StartsWith("System.Byte[]", StringComparison.Ordinal))
@@ -1182,4 +1182,4 @@ namespace Newtonsoft.Json
             return t;
         }
     }
-}
+}