This site has already been upgraded! 
This patch is a security and maintenance release, which focuses on fixing a couple of minor bugs, while adding some enhancements and a patch to a security vulnerability reported in the software. Therefore, it is important that you install this patch in a timely manner.
You can read the SMF topic here:
http://www.simplemachines.org/community/index.php?topic=548871.0SMF 2.0.12 July 7, 2016
===============================================================================
! Fixed word censor injection by disallowing an empty 'proper word'
! Fixed vulnerable unserialize() code by converting all instances to safe_unserialize()
! Added a more thorough safe_unserialize() function to prevent object injection
! Fixed a bug where leaving a custom profile field blank on registration that has an email mask would throw an error
! Fixed PayPal integration to comply with the new forced SSL
! Fixed a bug where notifications were sent for messages in inaccessible boards
! Fixed editor to make the editor work with Microsoft Edge
! Fixed issue where smiley popup is blank on iOS 9 devices
! Fixed WYSIWYG editor in mobile devices
! Fixed an undefined $_POST['icon'] in Sources/Post.php
! Fixed a minor bug in Login2()
! Fixed an issue where SMF doesn't recognize new domain names and considers these as invalid
! Fixed an issue where SMF would allow empty BBC
! Fixed an issue where theme variants could not be selected
! Fixed an issue where the file version of Subs-Post.php could have been 2.0.8 or 2.0.11. It will be updated to 2.0.12 in either case.
! Updated copyright year to 2016
