server-running-p: not detect server running by other emacs instance

[Liang Wang <netcasper@gmail.com>]

I modify server-running-p in server.el to make it to detect server
running by other emacs instance.  With this modification, server
started by first emacs instance won't be killed by successive
instances.

(unless (server-running-p)
  (server-start))

I replace server-socket-dir with (or server-socket-dir (format "/tmp/
emacs%d" (user-uid))) since server-socket-dir only set by server-
start.  Here is whole function.

(defun server-running-p  (&optional name)
  "Test whether server NAME is running."
  (interactive
   (list (if current-prefix-arg
	     (read-string "Server name: " nil nil server-name))))
  (unless name (setq name server-name))
  (condition-case nil
      (progn
	(delete-process
	 (make-network-process
	  :name "server-client-test" :family 'local :server nil :noquery t
	  :service (expand-file-name name (or server-socket-dir
					      (format "/tmp/emacs%d" (user-uid))))))
	t)
    (file-error nil)))

Does this make sense to be a patch to emacs?