remove the misleading prompt when connect without ip and port

Hi all,

When redis-cli re-connects (for example, reboot server and then reconnect) to redis-server without explicit ip and port, redis-cli will run cliConnect(1) and then send a "connect" command to the server (see redis-cli.c:942).
Then, redis-cli will show an error prompt "(error) ERR unknown command 'connect'", even if the connection is successful.
I think the prompt is misleading, and suggest to modify the codes around redis-cli.c:917, which is straightforward.

Best regards
Min Fu