Fix trex-431. Flow stat potential crash wihen stopping/deleting pg_id which does not exist
Fix trex-431. Flow stat potential crash wihen stopping/deleting pg_id which does not exist

Signed-off-by: Ido Barnea <3a6e28cf60eb2f9d9d6e5ab6275926d9a599fe66@cisco.com>

dimagol/trex-core,dimagol/trex-core,kisel/trex-core,dimagol/trex-core,kisel/trex-core,kisel/trex-core,kisel/trex-core,dimagol/trex-core,kisel/trex-core,kisel/trex-core,dimagol/trex-core,dimagol/trex-core