X-AMP: skip not working

As per https://github.com/atech/postal/wiki/Click-&-Open-Tracking#disable-tracking-on-a-per-e-mail-basis I included the header in an email to ignore click tracking in that message.

Unfortunately, it does not seem to have done anything.

Having a quick look in the code, I can see that that header is only checked here https://github.com/atech/postal/blob/6f29bc8d3f6f197d142724a7baee7376ff5fe8aa/lib/postal/message_db/message.rb#L548

Is the wiki wrong or is my understanding flawed?

The `+notrack` code worked perfectly.