BUG-2109 : remove also sessionId when bgp session is closed

Change-Id: I8f086b35ac3f75d9da04de37c0d88e465822077b
Signed-off-by: Dana Kutenicsova <dkutenic@cisco.com>
(cherry picked from commit 2fcfb689f55acd054033b08d837c7a2c239342b1)
Merge "BUG-2109 : remove also sessionId when bgp session is closed" into stable/helium