* Remove internal loop detection

I can't actually think of a situation where we can create an internal
loop. Sure externally triggered cycles can happen, but this is where the
*loop* plugin comes in that detects those.

Fixes #2602
Signed-off-by: Miek Gieben <miek@miek.nl>

* Remove test
Signed-off-by: Miek Gieben <miek@miek.nl>