org: Simplify doc

* lisp/org.el (org-end-of-meta-data): Drop unnecessary part around
"regular drawer".

Issue reported by Tom Davey.  https://orgmode.org/list/014801d7aa5c$c9057450$5b105cf0$@tomdavey.com

lisp/org.el

@@ -20714,8 +20714,7 @@ When optional argument FULL is t, also skip planning information,
 clocking lines and any kind of drawer.
 
 When FULL is non-nil but not t, skip planning information,
-clocking lines and only non-regular drawers, i.e. properties and
-logbook drawers."
+properties, clocking lines and logbook drawers."
   (org-back-to-heading t)
   (forward-line)
   ;; Skip planning information.