use esc_attr instead of attribute_escape

git-svn-id: https://plugins.svn.wordpress.org/get-all-pages-widget/trunk@931133 b8457f37-d9ea-0310-8a92-e5e31aec5664
release 1.2.2

git-svn-id: https://plugins.svn.wordpress.org/get-all-pages-widget/trunk@931134 b8457f37-d9ea-0310-8a92-e5e31aec5664