cbmultimanager assumes port 9092

cbmultimanager assumes that cbhealthagent RESI API is on port 9092 and offers no configuration option to specify otherwise.  However, the cbhealthagent supports a command-line option to change the HTTP port of the agent. 

 --http.port value                      Port that exposes the agent REST API. (default: 9092) 

cbmultimanager needs an option to specify a port