Define nndraft-close-server according to new calling conventions

* lisp/gnus/nnoo.el (nnoo-define-basics-1): *-close-server now
takes a DEFS parameter (bug#20319).

lisp/gnus/nnoo.el

@@ -277,11 +277,12 @@
      (nnoo-define-basics-1 ',backend)))
 
 (defun nnoo-define-basics-1 (backend)
-  (let ((functions '(close-server server-opened status-message)))
-    (while functions
-      (eval `(deffoo ,(nnoo-symbol backend (car functions))
-		 (&optional server)
-	       (,(nnoo-symbol 'nnoo (pop functions)) ',backend server)))))
+  (dolist (function '(server-opened status-message))
+    (eval `(deffoo ,(nnoo-symbol backend function) (&optional server)
+	     (,(nnoo-symbol 'nnoo function) ',backend server))))
+  (dolist (function '(close-server))
+    (eval `(deffoo ,(nnoo-symbol backend function) (&optional server defs)
+	     (,(nnoo-symbol 'nnoo function) ',backend server))))
   (eval `(deffoo ,(nnoo-symbol backend 'open-server)
 	     (server &optional defs)
 	   (nnoo-change-server ',backend server defs))))