Small wording change in CHANGELOG.txt.

CHANGELOG.txt

 
 Drupal 7.22, xxxx-xx-xx (development version)
 -----------------------
-- Changed various field API functions to allow them to be used to act on a
+- Changed various field API functions to allow them to optionally act on a
   single field within an entity (API addition: http://drupal.org/node/1825844).
 - Fixed a bug which prevented Drupal's file transfer functionality from working
   on some PHP 5.4 systems.