Can't register systems without a UUID
Description of problem:
We added a check for the dmi.system.uuid fact in
Author: Jonathon Turel <email@example.com>
Date: Thu Feb 28 16:10:05 2019 +0000
BZ #1652652 - Registering a system fails randomly (409 Conflict)
Fixes #26191 - Find existing system by UUID during registration
(cherry picked from commit 94fdc4456bffe91590be2294e90cad548f8dae24)
This prevents users from registering systems that don't have this fact set (like QEMU VMs).
I think the empty UUID should be specialcased here.
Steps to Reproduce:
1. start two VMs with QEMU
2. register both with subscription-manager
on second register, you get "HTTP error (500 - Internal Server Error): Multiple profiles found. Consider removing XXX which match this host."