T6287: Config-sync add the ability to configure API port

Add the ability to configure the API port if the API on the secondary
server works on a non-default port.
The primary node will connect to configured port for config-sync

set service config-sync secondary address '192.0.2.11'
set service config-sync secondary port '8443'

(cherry picked from commit a7c3f202ffea7859463f204cccf526f7517321f6)