BUG/MINOR: sock: do not double-close the accepted socket on the error path

Coverity found in issue #1646 that I added a double-close bug in last
commit e4d09cedb ("MINOR: sock: check configured limits at the sock layer,
not the listener's") because the error path already closes the FD. No
backport needed.

src/sock.c

@@ -104,7 +104,6 @@ struct connection *sock_accept_conn(struct listener *l, int *status)
 
 	if (likely(cfd != -1)) {
 		if (unlikely(cfd >= global.maxsock)) {
-			close(cfd);
 			send_log(p, LOG_EMERG,
 				 "Proxy %s reached the configured maximum connection limit. Please check the global 'maxconn' value.\n",
 				 p->id);