correct variable use that resulted in wrong title

git-svn-id: https://plugins.svn.wordpress.org/updraftplus/trunk@764734 b8457f37-d9ea-0310-8a92-e5e31aec5664
update readme

git-svn-id: https://plugins.svn.wordpress.org/updraftplus/trunk@764736 b8457f37-d9ea-0310-8a92-e5e31aec5664