Comment 11 for bug 1552071

To capture what I said in the now abandoned patch:

"This would change something that's not an error to an error, regardless of the weird latent behavior. Because of that, I think this would require a microversion which means we'd need a spec if we wanted to change this. gmann was compiling a list of random cleanup items for the compute API in an etherpad I believe, and this is something that could probably go in that list as a candidate for something to cleanup in a mass cleanup microversion."