Comet needs port number in the address

[rdragos]

When running the gRPC choreographer we need to provide the port number twice in order to connect to comet. Otherwise things fail silently. For eg:
comet --identity IP_ADDR:50001 --port 50001 works like a charm.

However, when running with
comet --identity IP_ADDR --port 50001 fails silently.

Looking at the debug logs with RUST_LOG=debug the computation outputs seem to be empty when comet is ran using the second version and we see no trace of error.