Minor edit about org-mac-link

Customizing whether Skim.app highlights the note no longer requires
using the Git version

org-contrib/org-mac-link.org

@@ -46,6 +46,6 @@
 
   You may customize which applications appear in the grab menu by customizing
   the group /org-mac-link/. Changes take effect immediately. If you are using
-  the latest org-mode from Git, you can also customize whether the
+  the org-mode version >=8.2, you can also customize whether the
   =org-mac-link= should highlight the selected text when grabbing the link from
   Skim.app.