remove wrong recaptcha images

git-svn-id: https://plugins.svn.wordpress.org/yikes-inc-easy-mailchimp-extender/trunk@961123 b8457f37-d9ea-0310-8a92-e5e31aec5664
remove all recaptcha images

git-svn-id: https://plugins.svn.wordpress.org/yikes-inc-easy-mailchimp-extender/trunk@961124 b8457f37-d9ea-0310-8a92-e5e31aec5664
re-add recaptcha images with appropriate image names

git-svn-id: https://plugins.svn.wordpress.org/yikes-inc-easy-mailchimp-extender/trunk@961125 b8457f37-d9ea-0310-8a92-e5e31aec5664