Adding RBAC role to connection does not affect existing connections

[Liam Young]

It seems that updating the role attribute of a connection has no affect on existing connections. For example when investigating another bug I needed to disable rbac but to get that to take effect I needed to either restart the southbound listener or the ovn-controller.

fwiw these are the steps I took to disable rbac (excluding the restart):

# ovn-sbctl find connection
_uuid : a3b68994-4376-4506-81eb-e23d15641305
external_ids : {}
inactivity_probe : 60000
is_connected : false
max_backoff : []
other_config : {}
read_only : false
role : ""
status : {}
target : "pssl:16642"

_uuid : ee53c2b6-ed8b-4b21-9825-a4ecaf2bdc95
external_ids : {}
inactivity_probe : 60000
is_connected : false
max_backoff : []
other_config : {}
read_only : false
role : ovn-controller
status : {}
target : "pssl:6642"

# ovn-sbctl set connection ee53c2b6-ed8b-4b21-9825-a4ecaf2bdc95 role='""'
# ovn-sbctl find connection
_uuid : a3b68994-4376-4506-81eb-e23d15641305
external_ids : {}
inactivity_probe : 60000
is_connected : false
max_backoff : []
other_config : {}
read_only : false
role : ""
status : {}
target : "pssl:16642"

_uuid : ee53c2b6-ed8b-4b21-9825-a4ecaf2bdc95
external_ids : {}
inactivity_probe : 60000
is_connected : false
max_backoff : []
other_config : {}
read_only : false
role : ""
status : {}
target : "pssl:6642"