Fix string in main file and use simple quotes in ChangeLog

git-svn-id: https://plugins.svn.wordpress.org/subscribe2/trunk@913523 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fix string in main file and use simple quotes in ChangeLog

git-svn-id: https://plugins.svn.wordpress.org/subscribe2/trunk@913526 b8457f37-d9ea-0310-8a92-e5e31aec5664