Fix "Not on a heading" error when setting priority inside a task

Changing the priority of a task when the point is after the heading
(anywhere inside the task) worked but aligning the tags failed with
a "not on a heading" error due to the save-excursion not including
the tag alignment.  This change moves back to the heading and
includes that during tag alignment to remove the error text.

Patch by Bernt Hansen.

lisp/ChangeLog

@@ -2,6 +2,8 @@
 
 	* org.el (org-adapt-indentation): Slightly improve the docstring.
 	(org-occur): Sends an error when the user inputs an empty string.
+	(org-priority): Bugfix: the tag alignement should happen within
+	save-excursion.
 
 	* org-exp.el (org-export-as-org): Use file-source.org format
 	instead of file.org-source.

lisp/org.el

@@ -10307,13 +10307,12 @@ ACTION can be `set', `up', `down', or a character."
 		(goto-char (match-end 2))
 		(insert " [#" news "]"))
 	    (goto-char (match-beginning 3))
-	    (insert "[#" news "] ")))))
-    (org-preserve-lc (org-set-tags nil 'align))
+	    (insert "[#" news "] "))))
+      (org-preserve-lc (org-set-tags nil 'align)))
     (if remove
 	(message "Priority removed")
       (message "Priority of current item set to %s" news))))
 
-
 (defun org-get-priority (s)
   "Find priority cookie and return priority."
   (save-match-data