Infinite loop cloning blueprint into itself

I ran into an issue where someone on my team was trying to create a subspace using a blueprint whose "space to clone" was the parent space, i.e. trying to clone the space into itself. Unsurprisingly, this didn't go well. At best, it led to a 502 error, at worst it created a nested string of spaces 100+ deep. (How the latter happened, I have no idea, I couldn't replicate that).

Obviously, people shouldn't really be doing this anyway, but better for thing not to break if they do. The patch below adds a check to avoid recursion in this scenario.