Removing DigitalSignature XML attribute form bundle

Removing DigitalSignature XML attribute form bundle.
This element reflected to Bundle.wxs causes a compilation error.

Author: alxcp

Source/src/WixSharp/Bootstrapper/Bundle.cs

@@ -110,7 +110,6 @@ public Bundle(string name, params ChainItem[] items)
         /// <summary>
         /// Parameters of digitaly sign
         /// </summary>
-        [Xml]
         public DigitalSignatureBootstrapper DigitalSignature;
 
         /// <summary>