add help banner on connection failure (ESL-25)

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@16040 d0543943-73ff-0310-b7d9-9358b9ac24b2

libs/esl/fs_cli.c

@@ -1154,6 +1154,7 @@ int main(int argc, char *argv[])
 	if (esl_connect(&handle, profile->host, profile->port, profile->pass)) {
 		esl_global_set_default_logger(7);
 		esl_log(ESL_LOG_ERROR, "Error Connecting [%s]\n", handle.err);
+		if (!argv_exec) usage(argv[0]);
 		return -1;
 	}