org-macs: org-with-limited-levels also change org-outline-regexp-at-bol

* lisp/org-macs.el (org-with-limited-levels): also modify, when
  appropriate, `org-outline-regexp-at-bol'

lisp/org-macs.el

@@ -347,7 +347,8 @@ point nowhere."
 
 (defmacro org-with-limited-levels (&rest body)
   "Execute BODY with limited number of outline levels."
-  `(let* ((org-outline-regexp (org-get-limited-outline-regexp)))
+  `(let* ((org-outline-regexp (org-get-limited-outline-regexp))
+	  (org-outline-regexp-at-bol (concat "^" org-outline-regexp)))
      ,@body))
 
 (defvar org-outline-regexp) ; defined in org.el