Move URL in the header higher so Package-Requires becomes the last keyword

Apparently, `package-read-from-string` doesn’t like it the old way.

org-clock-waybar.el

@@ -5,9 +5,9 @@
 
 ;; Author: Gergely Polonkai <gergely@polonkai.eu>
 ;; Keywords: org, clocking, waybar
-;; Version: 1.0
-;; Package-Requires: ((emacs "26.1"))
 ;; URL: https://gitea.polonkai.eu/gergely/org-clock-waybar
+;; Package-Version: 1.0
+;; Package-Requires: ((emacs "26.1") (org-mode "9"))
 
 ;; This program is free software; you can redistribute it and/or modify
 ;; it under the terms of the GNU General Public License as published by