Redis redis-cli cluster manager command host resolve behavior is weird

redis-cli cluster manager commands need host args, the host format can be:

ip:port
ip port

add-node first host can be both, second host must be ip:port;
del-node set-timeout call backup host must be ip:port;
info check fix reshard rebalance import host can be both.

If commands have only one arg, host can be both. if commands have more than one arg, host can only be ip:port. Maybe we should only allow ip:port, but this broke backward compatibillity.

But the error message alway is

"[ERR] Invalid arguments: you need to pass either a valid " \
    "address (ie. 120.0.0.1:7000) or space separated IP " \
    "and port (ie. 120.0.0.1 7000)\n"

This will cause ambiguity.