Fix order of nth and fix support for unlabeled endpoint

Author: Malabarba

cider.el

@@ -547,9 +547,10 @@ gets associated with it."
 (defun cider-select-endpoint ()
   "Interactively select the host and port to connect to."
   (dolist (ep cider-known-endpoints)
-    (unless (stringp (nth ep 2))
+    (unless (stringp (or (nth 2 ep)
+                         (nth 1 ep)))
       (user-error "The port for %s in `cider-known-endpoints' should be a string"
-                  (nth ep 0))))
+                  (nth 0 ep))))
   (let* ((ssh-hosts (cider--ssh-hosts))
          (hosts (seq-uniq (append (when cider-host-history
                                     ;; history elements are strings of the form "host:port"