add new donation link

git-svn-id: https://plugins.svn.wordpress.org/wp-database-backup/trunk@985171 b8457f37-d9ea-0310-8a92-e5e31aec5664
Tested up to: 4.0

git-svn-id: https://plugins.svn.wordpress.org/wp-database-backup/trunk@985180 b8457f37-d9ea-0310-8a92-e5e31aec5664