WIP: status completed crash

Signed-off-by: Eduardo Silva <eduardo@monkey.io>
Scheduler: on TRACE mode when closing connection, validate cs.

When trace mode is enabled through --trace, when the Scheduler will
close a connection, verify that no client_session associated exists
to the Scheduler entry, this condition may happen on bad API usage
by plugins.

Signed-off-by: Eduardo Silva <eduardo@monkey.io>