Small optimization

* lisp/org.el (org-find-property): Small optimization.

Since VALUE is included in the regexp, it doesn't need to be found
again with `org-entry-get'.  However, we still need to make sure match
really is a node property.

lisp/org.el

@@ -16341,7 +16341,7 @@ part of the buffer."
 	  (re (org-re-property property nil (not value) value)))
       (catch 'exit
 	(while (re-search-forward re nil t)
-	  (when (if value (equal value (org-entry-get (point) property nil t))
+	  (when (if value (org-at-property-p)
 		  (org-entry-get (point) property nil t))
 	    (throw 'exit (progn (org-back-to-heading t) (point)))))))))