Default instance of NamespaceTable is not used in Application encoderContext

[HiroSK80]

Original code: private EncoderContext encoderContext = new EncoderContext(new NamespaceTable(), new ServerTable(), StackUtils.getDefaultSerializer());

Fixed code: private EncoderContext encoderContext = new EncoderContext(NamespaceTable.getDefaultInstance(), new ServerTable(), StackUtils.getDefaultSerializer());