change readme.txt

git-svn-id: https://plugins.svn.wordpress.org/tr-cache-and-security/trunk@803804 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fix first login with out cookie

git-svn-id: https://plugins.svn.wordpress.org/tr-cache-and-security/trunk@804796 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fix first login with out cookie

git-svn-id: https://plugins.svn.wordpress.org/tr-cache-and-security/trunk@804869 b8457f37-d9ea-0310-8a92-e5e31aec5664