make sure to flush stdout every line read in monitor mode, to play well with redirection to file

src/redis-cli.c

@@ -291,6 +291,7 @@ static int cliSendCommand(int argc, char **argv, int repeat) {
         redisAppendCommandArgv(context,argc,(const char**)argv,argvlen);
         while (config.monitor_mode) {
             if (cliReadReply() != REDIS_OK) exit(1);
+            fflush(stdout);
         }
 
         if (config.pubsub_mode) {