org-compat: Fix org-directory-empty-p

* lisp/org-compat.el: Remove COUNT parameter in call of
directory-files.  COUNT not available in Emacs < 28.

lisp/org-compat.el

@@ -78,7 +78,7 @@
     (defun org-directory-empty-p (dir)
       "Return t if DIR names an existing directory containing no other files."
       (and (file-directory-p dir)
-           (null (directory-files dir nil directory-files-no-dot-files-regexp t 1))))
+           (null (directory-files dir nil directory-files-no-dot-files-regexp t))))
   (defalias 'org-directory-empty-p #'directory-empty-p))