This is in addition to checking if the own subscription comes back.
The duplicated lds subscription must come from a different client.
Added unit tests.
Also prefixed lds with '$' to mark it as system subject going forward.
This moves the loop detection check past other checks.
These checks should not trigger in cases where a loop is initially detected.
Fixes#1305
Signed-off-by: Matthias Hanel <mh@synadia.com>
6f77a54118