Fix sparse tree dispatch menu

* lisp/org.el (org-sparse-tree): Mention [r] in dispatch menu

lisp/org.el

@@ -11962,13 +11962,13 @@ T      Show entries with a specific TODO keyword.
 m      Show entries selected by a tags/property match.
 p      Enter a property name and its value (both with completion on existing
        names/values) and show entries with that property.
-/      Show entries matching a regular expression (`r' can be used as well)
+r      Show entries matching a regular expression (`/' can be used as well)
 d      Show deadlines due within `org-deadline-warning-days'.
 b      Show deadlines and scheduled items before a date.
 a      Show deadlines and scheduled items after a date."
   (interactive "P")
   (let (ans kwd value)
-    (message "Sparse tree: [/]regexp [t]odo [T]odo-kwd [m]atch [p]roperty [d]eadlines\n             [b]efore-date [a]fter-date")
+    (message "Sparse tree: [r]egexp [/]regexp [t]odo [T]odo-kwd [m]atch [p]roperty\n             [d]eadlines [b]efore-date [a]fter-date")
     (setq ans (read-char-exclusive))
     (cond
      ((equal ans ?d)