Clarification of http://www.openbsd.org/faq/upgrade42.html#Xup

Hi!

Thanks for a great update guide! But I still managed to make a crucial 
mistake while merging my X configuration files. In order to prevent 
similar problems for other users, I would recommend to add the following 
clarification under http://www.openbsd.org/faq/upgrade42.html#Xup

   Note that several files under /etc/X11 have already been updated
   from xbase42.tgz and xshare42.tgz above.

Best regards
/Johan Zandin
  Gothenburg, Sweden