- Added de_DE translation

git-svn-id: https://plugins.svn.wordpress.org/thumbs-rating/trunk@759104 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fix admin warning (with WP_DEBUG = true)

git-svn-id: https://plugins.svn.wordpress.org/thumbs-rating/trunk@759105 b8457f37-d9ea-0310-8a92-e5e31aec5664