console-server: Rationalise acquisition of console_id

It turns out we were also populating console->console_id in
`set_socket_info()`. Remove the open-coded acquisition in main(), as
it's not particularly useful beyond the call to `set_socket_info()`.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: I696d95157953f396a9ce65dd57d15daa66191118
diff --git a/console-server.c b/console-server.c
index fdf214f..c5596dd 100644
--- a/console-server.c
+++ b/console-server.c
@@ -756,12 +756,6 @@
 
 	console->tty_kname = config_tty_kname;
 
-	console->console_id = config_get_value(config, "socket-id");
-	if (!console->console_id) {
-		warnx("Error: The socket-id is not set in the config file");
-		return EXIT_FAILURE;
-	}
-
 	rc = tty_init(console, config);
 	if (rc) {
 		goto out_config_fini;