Fixing typo.


git-svn-id: https://plugins.svn.wordpress.org/akismet/trunk@873765 b8457f37-d9ea-0310-8a92-e5e31aec5664
Wording refinements.

* "is deleted automatically" flows better than "is automatically deleted."
* "trackback", not "track-back"



git-svn-id: https://plugins.svn.wordpress.org/akismet/trunk@873769 b8457f37-d9ea-0310-8a92-e5e31aec5664