ql:bundle-systems can cause infinite loop when the output bundle is in a system

[justinmeiners]

Description
If the destination directory for ql:bundle-systems is inside one of the include system folders, then this will start an infinite copying loop. A common case is if you are in a local project and run the command there.

Expected
It would be nice if this was a supported feature. If that doesn't make sense, I think it should at least present an error, instead of endlessly creating files.