Accounts for nodejs fix to "reversing" pseudo-header order in 17.5.0 and 16.14.1
We have a bug in SecretAgent that status codes > 599 will result in nodejs throwing an error that it can't handle that status code. Chrome, however, will accept status codes outside the range of valid codes. I can't find any way in node.js to use a >599 status code besides writing directly to the socket, which means we're writing all of our own http2 code at that point. In the interim, I think we should just set to 599 and warn. This is a detectable item if someone knows to look for it.